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Sample records for 2-5 times greater

  1. TWOS - TIME WARP OPERATING SYSTEM, VERSION 2.5.1

    NASA Technical Reports Server (NTRS)

    Bellenot, S. F.

    1994-01-01

    The Time Warp Operating System (TWOS) is a special-purpose operating system designed to support parallel discrete-event simulation. TWOS is a complete implementation of the Time Warp mechanism, a distributed protocol for virtual time synchronization based on process rollback and message annihilation. Version 2.5.1 supports simulations and other computations using both virtual time and dynamic load balancing; it does not support general time-sharing or multi-process jobs using conventional message synchronization and communication. The program utilizes the underlying operating system's resources. TWOS runs a single simulation at a time, executing it concurrently on as many processors of a distributed system as are allocated. The simulation needs only to be decomposed into objects (logical processes) that interact through time-stamped messages. TWOS provides transparent synchronization. The user does not have to add any more special logic to aid in synchronization, nor give any synchronization advice, nor even understand much about how the Time Warp mechanism works. The Time Warp Simulator (TWSIM) subdirectory contains a sequential simulation engine that is interface compatible with TWOS. This means that an application designer and programmer who wish to use TWOS can prototype code on TWSIM on a single processor and/or workstation before having to deal with the complexity of working on a distributed system. TWSIM also provides statistics about the application which may be helpful for determining the correctness of an application and for achieving good performance on TWOS. Version 2.5.1 has an updated interface that is not compatible with 2.0. The program's user manual assists the simulation programmer in the design, coding, and implementation of discrete-event simulations running on TWOS. The manual also includes a practical user's guide to the TWOS application benchmark, Colliding Pucks. TWOS supports simulations written in the C programming language. It is designed

  2. Time Warp Operating System, Version 2.5.1

    NASA Technical Reports Server (NTRS)

    Bellenot, Steven F.; Gieselman, John S.; Hawley, Lawrence R.; Peterson, Judy; Presley, Matthew T.; Reiher, Peter L.; Springer, Paul L.; Tupman, John R.; Wedel, John J., Jr.; Wieland, Frederick P.; Younger, Herbert C.

    1993-01-01

    Time Warp Operating System, TWOS, is special purpose computer program designed to support parallel simulation of discrete events. Complete implementation of Time Warp software mechanism, which implements distributed protocol for virtual synchronization based on rollback of processes and annihilation of messages. Supports simulations and other computations in which both virtual time and dynamic load balancing used. Program utilizes underlying resources of operating system. Written in C programming language.

  3. Monitoring PM2.5 in the Atmosphere by Using Terahertz Time-Domain Spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhan, Honglei; Zhao, Kun; Bao, Rima; Xiao, Lizhi

    2016-09-01

    The real-time monitoring of the air pollution with multiple sources is of great significance for pollution control and environmental protection. In this paper, we presented a study of terahertz time-domain spectroscopy (THz-TDS) as a direct tool for monitoring the component and content of PM2.5 in atmosphere. Due to the THz absorption, the intensities of the peaks in THz-TDS decreased with the augment of PM2.5 and were proportional to the PM2.5 content. The ratio of absorbance A to PM2.5 reflected a basically unchanged tendency, indicating the little change of principal elements under the pollution degree. In the high-pollution condition, a lot of SO2 from vehicle and factory was emitted into air. The elements, such as S and O from anions, had a stronger absorption effect in THz range. Based on the absorbance spectra, the absorption tendencies with PM2.5 over the whole range were validated by principal component analysis and the quantitative model with a high correlation was built by using back propagation artificial neural network. BPANN model improved the precision of linear fitting between peak intensities and PM2.5. The research demonstrates that THz-TDS is a promising tool for fast, direct, and reliable monitoring in environmental applications.

  4. Time Course of Heart Rate Variability Response to PM2.5 Exposure from Secondhand Smoke

    PubMed Central

    Garza, Jennifer L.; Mittleman, Murray A.; Zhang, Jinming; Christiani, David C.; Cavallari, Jennifer M

    2016-01-01

    Purpose: Exposure to secondhand smoke (SHS) has been associated with decreased heart rate variability (HRV). However, the time course of this association is unclear. Therefore, the objective of this study was to investigate the association between 15–240 minute SHS-related fine particulate matter (PM2.5) moving averages and indices of HRV. Methods: With a panel study design, we used personal monitors to continuously measure PM2.5 and HRV of 35 participants who were exposed to SHS for approximately 6 hours. Results: We observed negative, significant associations between 5-minute HRV indices and 15 minute PM2.5 moving averages and 240 minute PM2.5 moving averages: there was a significant (p<0.01) 7.5% decrease in the 5-minute square root of the mean squared differences of successive normal heart beats associated with (RMSSD), and a significant (p<0.01) 14.7% decrease in the 5-minute high frequency (HF) power associated with the 15 minute PM2.5 moving averages; there was also a significant (p<0.01) 46.9% decrease in the 5-minute RMSSD, and a significant (p<0.01) 77.7% decrease in the 5-minute high frequency (HF) power associated with the 240 minute PM2.5 moving averages. Conclusions: Our findings that exposure to SHS related PM2.5 was associated with HRV support the hypothesis that SHS can affect the cardiovascular system. The negative associations reported between short and longer term PM2.5 and HRV indicate adverse effects of SHS on the cardiovascular system. PMID:27223894

  5. Asymmetric multiscale behavior in PM2.5 time series: Based on asymmetric MS-DFA

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Ni, Zhiwei; Ni, Liping

    2016-11-01

    Particulate matter with an aerodynamic diameter of 2.5 mm or less (PM2.5) is one of the most serious air pollution, considered most harmful for people by World Health Organisation. In this paper, we utilized the asymmetric multiscale detrended fluctuation analysis (A-MSDFA) method to explore the existence of asymmetric correlation properties for PM2.5 daily average concentration in two USA cities (Fresno and Los Angeles) and two Chinese cities (Hong Kong and Shanghai), and to assess the properties of these asymmetric correlations. The results show the existences of asymmetric correlations, and the degree of asymmetric for two USA cities is stronger than that of two Chinese cities. Further, most of the local exponent β(n) are smaller than 0.5, which indicates the existence of anti-persistent long-range correlation for PM2.5 time series in four cities. In addition, we reanalyze the asymmetric correlation by the A-MSDFA method with secant rolling windows of different sizes, which can investigate dynamic changes in the multiscale correlation for PM2.5 time series with changing window size. Whatever window sizes, the correlations are asymmetric and display smaller asymmetries at small scales and larger asymmetries at large scales. Moreover, the asymmetries become increasingly weaker with the increase of window sizes.

  6. Comparing Gravimetric and Real-Time Sampling of PM2.5 Concentrations Inside Truck Cabins

    PubMed Central

    Zhu, Ying; Smith, Thomas J.; Davis, Mary E.; Levy, Jonathan I.; Herrick, Robert; Jiang, Hongyu

    2012-01-01

    As part of a study on truck drivers’ exposure and health risk, pickup and delivery (P&D) truck drivers’ on-road exposure patterns to PM2.5 were assessed in five weeklong sampling trips in metropolitan areas of five U.S. cities from April to August of 2006. Drivers were sampled with real-time (DustTrak) and gravimetric samplers to measure average in-cabin PM2.5 concentrations and to compare their correspondence in moving trucks. In addition, GPS measurements of truck locations, meteorological data, and driver behavioral data were collected throughout the day to determine which factors influence the relationship between real-time and gravimetric samplers. Results indicate that the association between average real-time and gravimetric PM2.5 measurements on moving trucks was fairly consistent (Spearman rank correlation of 0.63), with DustTrak measurements exceeding gravimetric measurements by approximately a factor of 2. This ratio differed significantly only between the industrial Midwest cities and the other three sampled cities scattered in the South and West. There was also limited evidence of an effect of truck age. Filter samples collected concurrently with DustTrak measurements can be used to calibrate average mass concentration responses for the DustTrak, allowing for real-time measurements to be integrated into longer-term studies of inter-city and intra-urban exposure patterns for truck drivers. PMID:21991940

  7. Comparing gravimetric and real-time sampling of PM(2.5) concentrations inside truck cabins.

    PubMed

    Zhu, Ying; Smith, Thomas J; Davis, Mary E; Levy, Jonathan I; Herrick, Robert; Jiang, Hongyu

    2011-11-01

    As part of a study on truck drivers' exposure and health risk, pickup and delivery (P&D) truck drivers' on-road exposure patterns to PM(2.5) were assessed in five, weeklong sampling trips in metropolitan areas of five U.S. cities from April to August of 2006. Drivers were sampled with real-time (DustTrak) and gravimetric samplers to measure average in-cabin PM(2.5) concentrations and to compare their correspondence in moving trucks. In addition, GPS measurements of truck locations, meteorological data, and driver behavioral data were collected throughout the day to determine which factors influence the relationship between real-time and gravimetric samplers. Results indicate that the association between average real-time and gravimetric PM(2.5) measurements on moving trucks was fairly consistent (Spearman rank correlation of 0.63), with DustTrak measurements exceeding gravimetric measurements by approximately a factor of 2. This ratio differed significantly only between the industrial Midwest cities and the other three sampled cities scattered in the South and West. There was also limited evidence of an effect of truck age. Filter samples collected concurrently with DustTrak measurements can be used to calibrate average mass concentration responses for the DustTrak, allowing for real-time measurements to be integrated into longer-term studies of inter-city and intra-urban exposure patterns for truck drivers.

  8. Asymmetric multifractal detrending moving average analysis in time series of PM2.5 concentration

    NASA Astrophysics Data System (ADS)

    Zhang, Chen; Ni, Zhiwei; Ni, Liping; Li, Jingming; Zhou, Longfei

    2016-09-01

    In this paper, we propose the asymmetric multifractal detrending moving average analysis (A-MFDMA) method to explore the asymmetric correlation in non-stationary time series. The proposed method is applied to explore the asymmetric correlation of PM2.5 daily average concentration with uptrends or downtrends in China. In addition, shuffling and phase randomization procedures are applied to detect the sources of multifractality. The results show that existences of asymmetric correlations, and the asymmetric correlations are multifractal. Further, the multifractal scaling behavior in the Chinese PM2.5 is caused not only by long-range correlation but also by fat-tailed distribution, but the major source of multifractality is fat-tailed distribution.

  9. Real-Time Estimation of Satellite-Derived PM2.5 Based on a Semi-Physical Geographically Weighted Regression Model

    PubMed Central

    Zhang, Tianhao; Liu, Gang; Zhu, Zhongmin; Gong, Wei; Ji, Yuxi; Huang, Yusi

    2016-01-01

    The real-time estimation of ambient particulate matter with diameter no greater than 2.5 μm (PM2.5) is currently quite limited in China. A semi-physical geographically weighted regression (GWR) model was adopted to estimate PM2.5 mass concentrations at national scale using the Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Depth product fused by the Dark Target (DT) and Deep Blue (DB) algorithms, combined with meteorological parameters. The fitting results could explain over 80% of the variability in the corresponding PM2.5 mass concentrations, and the estimation tends to overestimate when measurement is low and tends to underestimate when measurement is high. Based on World Health Organization standards, results indicate that most regions in China suffered severe PM2.5 pollution during winter. Seasonal average mass concentrations of PM2.5 predicted by the model indicate that residential regions, namely Jing-Jin-Ji Region and Central China, were faced with challenge from fine particles. Moreover, estimation deviation caused primarily by the spatially uneven distribution of monitoring sites and the changes of elevation in a relatively small region has been discussed. In summary, real-time PM2.5 was estimated effectively by the satellite-based semi-physical GWR model, and the results could provide reasonable references for assessing health impacts and offer guidance on air quality management in China. PMID:27706054

  10. Real-time particle monitor calibration factors and PM2.5 emission factors for multiple indoor sources.

    PubMed

    Dacunto, Philip J; Cheng, Kai-Chung; Acevedo-Bolton, Viviana; Jiang, Ruo-Ting; Klepeis, Neil E; Repace, James L; Ott, Wayne R; Hildemann, Lynn M

    2013-08-01

    Indoor sources can greatly contribute to personal exposure to particulate matter less than 2.5 μm in diameter (PM2.5). To accurately assess PM2.5 mass emission factors and concentrations, real-time particle monitors must be calibrated for individual sources. Sixty-six experiments were conducted with a common, real-time laser photometer (TSI SidePak™ Model AM510 Personal Aerosol Monitor) and a filter-based PM2.5 gravimetric sampler to quantify the monitor calibration factors (CFs), and to estimate emission factors for common indoor sources including cigarettes, incense, cooking, candles, and fireplaces. Calibration factors for these indoor sources were all significantly less than the factory-set CF of 1.0, ranging from 0.32 (cigarette smoke) to 0.70 (hamburger). Stick incense had a CF of 0.35, while fireplace emissions ranged from 0.44-0.47. Cooking source CFs ranged from 0.41 (fried bacon) to 0.65-0.70 (fried pork chops, salmon, and hamburger). The CFs of combined sources (e.g., cooking and cigarette emissions mixed) were linear combinations of the CFs of the component sources. The highest PM2.5 emission factors per time period were from burned foods and fireplaces (15-16 mg min(-1)), and the lowest from cooking foods such as pizza and ground beef (0.1-0.2 mg min(-1)). PMID:23784066

  11. Refined Assessment of Human PM2.5 Exposure in Chinese city by Incorporating Time-activity Data

    NASA Astrophysics Data System (ADS)

    Zhu, W.; Wang, H.

    2015-12-01

    Since urban residents tend to spend a majority of time indoors throughout a day, it has been widely discussed in recent years, whether fixed-site monitoring PM2.5 ambient concentration is feasible as a surrogate of human PM2.5 exposure. Comprehensive understanding of residents' daily time-activity patterns (TAP) and possible indoor behavior are urgently needed to perform a more accurate estimate of human PM2.5exposure, especially in China, where is experiencing rapid urbanization.Field surveys of TAP were carried out in a Chinese city of Suzhou from 2014 to 2015 to evaluate PM2.5 exposure in various micro-environments (ME, e.g., residence, outdoors and in-transit). We gathered and analyzed urban residents' seasonal time-activity data using 24h retrospective time-location diaries, as well as diversified exposure-related indoor information (e.g. ventilation, environment tobacco smoke and cooking). PM2.5exposure is calculated through the incorporation of ambient concentration data, modified indoor/outdoor empirical functions and TAP. The spatial distributions of TAP-based exposure and static-population based exposure are also compared.Residents in Suzhou urban area spend over 65% of time at home and 90% indoors. There are significant temporal (season, day type) and socioeconomic differences (gender, age, education, living alone, having children at home, employment status, etc.) of time-activity distributions, which makes the sum of PM2.5 ME exposure differs notably from static-population based ambient exposure. People prefer to spend more time at home both in winter (P<0.05) and on weekends (P<0.001), less time outdoors in winter but more on weekends (P<0.001). Gender, education and living alone are negative associated with time spent home, while age, children at home and employment status are positively related. On the other hand, due to lack of monitoring stations in unban Suzhou, the inverse distance squared weighting method is not ideally performed and may be less

  12. Source Identification of PM2.5 in Steubenville, Ohio Using a Hybrid Method for Highly Time-resolved Data

    EPA Science Inventory

    A new source-type identification method, Reduction and Species Clustering Using Episodes (ReSCUE), was developed to exploit the temporal synchronicity between species to form clusters of species that vary together. High time-resolution (30 min) PM2.5 sampling was condu...

  13. PM2.5 Characterization for Time Series Studies: Pointwise Uncertainty Estimation and Bulk Speciation Methods Applied in Denver

    PubMed Central

    Dutton, Steven J.; Schauer, James J.; Vedal, Sverre; Hannigan, Michael P.

    2009-01-01

    Many studies have identified associations between adverse health effects and short-term exposure to particulate matter less than 2.5 microns in diameter (PM2.5). These effects, however, are not consistent across geographical regions. This may be due in part to variations in the chemical make-up of PM2.5 resulting from unique combinations of sources, both primary and secondary, in different regions. The Denver Aerosol Sources and Health (DASH) study is a multi-year time series study designed to characterize the daily chemical composition of PM2.5 in Denver, identify the major contributing sources, and investigate associations between sources and a broad array of adverse health outcomes. Measurement methodology, field blank correction, pointwise uncertainty estimation and detection limit consideration are discussed in the context of bulk speciation for the DASH study. Results are presented for the first 4.5 years of mass, inorganic ion and bulk carbon speciation. The derived measurement uncertainties were propagated using the root sum of squares method and show good agreement with precision estimates derived from bi-weekly duplicate samples collected on collocated samplers. Gravimetric mass has the most uncertainty of any measurement and reconstructed mass generated from the sum of the individual species shows less uncertainty than measured mass on average. The methods discussed provide a good framework for PM2.5 speciation measurements and are generalizable to analysis of other environmental measures. PMID:20126292

  14. Victims' Time Discounting 2.5 Years after the Wenchuan Earthquake: An ERP Study

    PubMed Central

    Feng, Chun-Liang; Wang, Wen-Zhong; Du, Bo-Qi; Gan, Tian; Luo, Yue-Jia

    2012-01-01

    Background Time discounting refers to the fact that the subjective value of a reward decreases as the delay until its occurrence increases. The present study investigated how time discounting has been affected in survivors of the magnitude-8.0 Wenchuan earthquake that occurred in China in 2008. Methodology Nineteen earthquake survivors and 22 controls, all school teachers, participated in the study. Event-related brain potentials (ERPs) for time discounting tasks involving gains and losses were acquired in both the victims and controls. Findings The behavioral data replicated our previous findings that delayed gains were discounted more steeply after a disaster. ERP results revealed that the P200 and P300 amplitudes were increased in earthquake survivors. There was a significant group (earthquake vs. non- earthquake) × task (gain vs. loss) interaction for the N300 amplitude, with a marginally significantly reduced N300 for gain tasks in the experimental group, which may suggest a deficiency in inhibitory control for gains among victims. Conclusions The results suggest that post-disaster decisions might involve more emotional (System 1) and less rational thinking (System 2) in terms of a dual-process model of decision making. The implications for post-disaster intervention and management are also discussed. PMID:22792277

  15. Time-resolved measurements of PM2.5 carbonaceous aerosols at Gosan, Korea.

    PubMed

    Batmunkh, T; Kim, Y J; Lee, K Y; Cayetano, M G; Jung, J S; Kim, S Y; Kim, K C; Lee, S J; Kim, J S; Chang, L S; An, J Y

    2011-11-01

    In order to better understand the characteristics of atmospheric carbonaceous aerosol at a background site in Northeast Asia, semicontinuous organic carbon (OC) and elemental carbon (EC), and time-resolved water-soluble organic carbon (WSOC) were measured by a Sunset OC/ EC and a PILS-TOC (particle-into-liquid sampler coupled with an online total organic carbon) analyzer, respectively, at the Gosan supersite on Jeju Island, Korea, in the summer (May 28-June 17) and fall (August 24-September 30) of 2009. Hourly average OC concentration varied in the range of approximately 0.87-28.38 microgC m-3, with a mean of 4.07+/- 2.60 microgC m-3, while the hourly average EC concentration ranged approximately from 0.04 to 8.19 .microgC m-3, with a mean of 1.35 +/- 0.71 microgC m-3, from May 28 to June 17, 2009. During the fall season, OC varied in the approximate range 0.9-9.6 microgC m-3, with a mean of 2.30 +/-0.80 microgC m-3, whereas EC ranged approximately from 0.01 to 5.40 microgC m-3, with a mean of 0.66 +/- 0.38 microgC m-3. Average contributions of EC to TC and WSOC to OC were 26.0% +/- 9.7% and 20.6% +/-7.4%, and 37.6% +/- 23.5% and 57.2% +/- 22.2% during summer and fall seasons, respectively. As expected, clear diurnal variation of WSOC/OC was found in summer, varying from 0.22 during the nighttime up to 0.72 during the daytime, mainly due to the photo-oxidation process. In order to investigate the effect of air mass pathway on the characteristics of carbonaceous aerosol, 5-day back-trajectory analysis was conducted using the HYSPLIT model. The air mass pathways were classified into four types: Continental (CC), Marine (M), East Sea (ES) and Korean Peninsula (KP). The highest OC/EC ratio of 3.63 was observed when air mass originated from the Continental area (CC). The lowest OC/EC ratio of 0.79 was measured when air mass originated from the Marine area (M). A high OC concentration was occasionally observed at Gosan due to local biomass burning activities. The

  16. Measurement, time series analysis and source apportionment of inorganic and organic speciated PM(2.5) air pollution in Denver

    NASA Astrophysics Data System (ADS)

    Dutton, Steven James

    Particulate air pollution has demonstrated significant health effects ranging from worsening of asthma to increased rates of respiratory and cardiopulmonary mortality. These results have prompted the US-EPA to include particulate matter (PM) as one of the six criteria air pollutants regulated under the Clean Air Act. The diverse chemical make-up and physical characteristics of PM make it a challenging pollutant to characterize and regulate. Particulate matter less than 2.5 microns in diameter (PM2.5) has the ability to travel deep into the lungs and therefore has been linked with some of the more significant health effects. The toxicity of any given particle is likely dependent on its chemical composition. The goal of this project has been to chemically characterize a long time series of PM 2.5 measurements collected at a receptor site in Denver to a level of detail that has not been done before on this size data set. This has involved characterization of inorganic ions using ion chromatography, total elemental and organic carbon using thermal optical transmission, and organic molecular marker species using gas chromatography-mass spectrometry. Methods have been developed to allow for daily measurement and speciation for these compounds over a six year period. Measurement methods, novel approaches to uncertainty estimation, time series analysis, spectral and pattern analyses and source apportionment using two multivariate factor analysis models are presented. Analysis results reveal several natural and anthropogenic sources contributing to PM2.5 in Denver. The most distinguishable sources are motor vehicles and biomass combustion. This information will be used in a health effect analysis as part of a larger study called the Denver Aerosol Sources and Health (DASH) study. Such results will inform regulatory decisions and may help create a better understanding of the underlying mechanisms for the observed adverse health effects associated with PM2.5.

  17. Source identification of PM2.5 in Steubenville, Ohio using a hybrid method for highly time-resolved data.

    PubMed

    Vedantham, Ram; Landis, Matthew S; Olson, David; Pancras, Joseph Patrick

    2014-01-01

    A new source-type identification method, Reduction and Species Clustering Using Episodes (ReSCUE), was developed to exploit the temporal synchronicity typically observed between ambient species in high time resolution fine particulate matter (PM2.5) data to form clusters that vary together. High time-resolution (30 min) PM2.5 sampling was conducted for a month during the summer of 2006 in Steubenville, OH, an EPA designated nonattainment area for the U.S. National Ambient Air Quality Standards (NAAQS). When the data were evaluated, the species clusters from ReSCUE matched extremely well with the source types identified by EPA Unmix demonstrating that ReSCUE is a valuable tool in identifying source types. Results from EPA Unmix show that contributions to PM2.5 are mostly from iron/steel manufacturing (36% ± 9%), crustal matter (33% ± 11%), and coal combustion (11% ± 19%). More importantly, ReSCUE was useful in (i) providing objective data driven guidance for the number of source factors and key fitting species for EPA Unmix, and (ii) detecting tenuous associations between some species and source types in the results derived by EPA Unmix.

  18. Coping Skills Help Explain How Future-Oriented Adolescents Accrue Greater Well-Being Over Time.

    PubMed

    Chua, Li Wen; Milfont, Taciano L; Jose, Paul E

    2015-11-01

    Adolescents who endorse greater levels of future orientation report greater well-being over time, but we do not know the mechanism by which this happens. The present longitudinal study examined whether both adaptive as well as maladaptive coping strategies might explain how future orientation leads to ill-being and well-being over time in young New Zealanders. A sample of 1,774 preadolescents and early adolescents (51.9 % female) aged 10-15 years at Time 1 completed a self-report survey three times with 1 year intervals in between. Longitudinal mediation path models were constructed to determine whether and how maladaptive and adaptive coping strategies at Time 2 functioned as mediators between future orientation at Time 1 and ill-being and well-being at Time 3. Results showed that future orientation predicted lower maladaptive coping, which in turn predicted lower substance use and self-harming behavior. All three well-being outcomes (i.e., happiness with weight, vitality, and sleep) were consistently predicted by future orientation, and all three pathways were mediated by both lower maladaptive and higher adaptive coping strategies (with the exception of happiness with weight, which was mediated only by lower maladaptive coping). The results suggest that several pathways by which future orientation leads to greater well-being occurs through an increased use of adaptive coping, a decreased use of maladaptive coping, or both.

  19. Time of fusion of greater cornu with body of hyoid bone in Northwest Indians.

    PubMed

    Harjeet, Kaur; Synghal, Sanjeev; Kaur, Gagandeep; Aggarwal, Anjali; Wahee, Pratima

    2010-09-01

    Time of fusion of hyoid is of considerable interest for forensic experts in estimating the age of an individual when unrecognized decomposed bodies or skeletal remains are available. The present investigation was carried out to study the age of fusion in 200 hyoid bones (133 males and 67 females) varying in age from 18 to 85years. Fusion of greater cornu with the body of the hyoid bone was not seen till the age of 25years in both sexes. In the males complete fusion was seen in 22(16.5%) bilaterally and 16(6.0%) unilaterally while in females it was observed in 18(26.9%) bilaterally and 10(7.5%) unilaterally. No significant sexual and side differences were found between the incidence of fusion of greater cornu with the body of hyoid in almost all the age groups except in the last age group (61 & above) where the sexual difference was highly significant (p<0.001) in unilateral complete fusion and in total cases in bilateral complete fusion (p<0.01). The lesser cornu was not fused with the junction or with greater cornu till the age of 35years in males and 40years in females. The maximum incidence of fusion of lesser cornu was observed in last age group of 61years and above (55.6% males and 66.7% females). In conclusion estimation of age by using hyoid bone is not reliable as time of fusion of greater cornu with the body of hyoid is irregular. Subjects above the age of 60 years had either unilateral (13.2%) or bilateral (42.1%) nonfusion or also fusion (21.1% bilateral, 13.2% unilateral). The present method can be a supplementary approach for estimating age when the other skeletal remains are not available. PMID:20630786

  20. Investigation of the time evolved spatial distribution of urban PM2.5 concentrations and aerosol composition during episodic high PM events in Yuma, AZ

    NASA Astrophysics Data System (ADS)

    Holmes, Heather A.; Pardyjak, Eric R.; Tyler, Bonnie J.; Peterson, Richard E.

    An interdisciplinary field study designed to investigate the spatial and temporal variability of atmospheric aerosols during high particulate matter ( PM) events along the US-Mexico border near Yuma, AZ was run during the week of March 18, 2007. The experiments were designed to quantify chemical composition and physical phenomena governing the transport of aerosols generated from episodic high PM events. The field study included two micrometeorological monitoring sites; one rural and one urban, equipped with sonic anemometers, continuous particulate concentration monitors and ambient aerosol collection equipment. In addition to the two main monitoring sites, five additional locations were equipped with optical particle counters to allow for the investigation of the spatial and temporal distribution of PM2.5 in the urban environment. In this paper, the meteorological and turbulence parameters governing the distribution and concentration of PM2.5 in the urban environment for two high-wind erosion events and one burning event are compared. The interaction between local atmospheric conditions and the particulate distribution is investigated. Results indicate that a single point measurement in the urban area of Yuma may not be sufficient for determining the ambient PM concentrations that the local population experiences; all three high PM events indicated PM2.5 varied considerably with maximum urban concentrations 5-10 times greater than the measured minima. A comparison of inorganic and carbonaceous content of the aerosols for the three high PM events is presented. The comparison shows an increase in silicon during crustal dust events and an increase in elemental and organic carbon during the burn event. Additional surface chemistry analysis, using time-of-flight secondary ion mass spectrometry (ToF-SIMS), for aerosols collected at the urban and rural sites during the burn event are discussed. The surface chemistry analysis provides positive ion mass spectra of organic

  1. Resonance Raman study of the A-band short-time photodissociation dynamics of 2,5-di-iodothiophene

    SciTech Connect

    Ruan Caibin; Zhu Hailin; Wang Huigang; Zheng Xuming; Phillips, David Lee

    2008-12-07

    Resonance Raman spectra were obtained for 2,5-di-iodothiophene in cyclohexane solution with excitation wavelengths in resonance with its A-band absorption. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion mostly along the nominal symmetric C{sub 2}C{sub 3}/C{sub 4}C{sub 5} stretch {nu}{sub 2} (1388 cm{sup -1}) of the thienyl ring and this is accompanied by motions along the nominal symmetric CSC stretch {nu}{sub 6} (640 cm{sup -1}), the nominal symmetric C-I stretch {nu}{sub 7} (187 cm{sup -1}), the nominal antisymmetric CSC stretch {nu}{sub 19} (728 cm{sup -1}), the nominal antisymmetric C{sub 2}C{sub 3}/C{sub 4}C{sub 5} stretch {nu}{sub 16} (1497 cm{sup -1}), the nominal C{sub 3}C{sub 4} stretch {nu}{sub 3} (1286 cm{sup -1}) and four other vibrational modes. A preliminary resonance Raman intensity analysis was done and the results for 2,5-di-iodothiophene were compared to previous results for 2-iodothiophene and di-iodomethane to discuss the mechanism of the symmetric breaking in the initial A-band photodissociation dynamics of 2,5-di-iodothiophene and 2-iodothiophene.

  2. Characteristics and sensitivity analysis of multiple-time-resolved source patterns of PM2.5 with real time data using Multilinear Engine 2

    NASA Astrophysics Data System (ADS)

    Peng, Xing; Shi, Guo-Liang; Gao, Jian; Liu, Jia-Yuan; HuangFu, Yan-Qi; Ma, Tong; Wang, Hai-Ting; Zhang, Yue-Chong; Wang, Han; Li, Hui; Ivey, Cesunica E.; Feng, Yin-Chang

    2016-08-01

    With real time resolved data of Particulate matter (PM) and chemical species, understanding the source patterns and chemical characteristics is critical to establish controlling of PM. In this work, PM2.5 and chemical species were measured by corresponding online instruments with 1-h time resolution in Beijing. Multilinear Engine 2 (ME2) model was applied to explore the sources, and four sources (vehicle emission, crustal dust, secondary formation and coal combustion) were identified. To investigate the sensitivity of time resolution on the source contributions and chemical characteristics, ME2 was conducted with four time resolution runs (1-h, 2-h, 4-h, and 8-h). Crustal dust and coal combustion display large variation in the four time resolutions runs, with their contributions ranging from 6.7 to 10.4 μg m-3 and from 6.4 to 12.2 μg m-3, respectively. The contributions of vehicle emission and secondary formation range from 7.5 to 10.5 and from 14.7 to 16.7 μg m-3, respectively. The sensitivity analyses were conducted by principal component analysis-plot (PCA-plot), coefficient of divergence (CD), average absolute error (AAE) and correlation coefficients. For the four time resolution runs, the source contributions and profiles of crustal dust and coal combustion were more unstable than other source categories, possibly due to the lack of key markers of crustal dust and coal combustion (e.g. Si, Al). On the other hand, vehicle emission and crustal dust were more sensitive to time series of source contributions at different time resolutions. Findings in this study can improve our knowledge of source contributions and chemical characteristics at different time solutions.

  3. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  4. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress

    PubMed Central

    Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-01-01

    Abstract Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75‐min recovery. RT measures were generated from an ex‐Gaussian distribution that yielded three predictors: mu‐RT, sigma‐RT, and tau‐RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = −.009, SE = .005, p = .09) and diastolic (B = −.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = −.007, SE = .003, p = .03) and impaired vagal tone (B = −.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses. PMID:26894967

  5. Decreased reaction time variability is associated with greater cardiovascular responses to acute stress.

    PubMed

    Wawrzyniak, Andrew J; Hamer, Mark; Steptoe, Andrew; Endrighi, Romano

    2016-05-01

    Cardiovascular (CV) responses to mental stress are prospectively associated with poor CV outcomes. The association between CV responses to mental stress and reaction times (RTs) in aging individuals may be important but warrants further investigation. The present study assessed RTs to examine associations with CV responses to mental stress in healthy, older individuals using robust regression techniques. Participants were 262 men and women (mean age = 63.3 ± 5.5 years) from the Whitehall II cohort who completed a RT task (Stroop) and underwent acute mental stress (mirror tracing) to elicit CV responses. Blood pressure, heart rate, and heart rate variability were measured at baseline, during acute stress, and through a 75-min recovery. RT measures were generated from an ex-Gaussian distribution that yielded three predictors: mu-RT, sigma-RT, and tau-RT, the mean, standard deviation, and mean of the exponential component of the normal distribution, respectively. Decreased intraindividual RT variability was marginally associated with greater systolic (B = -.009, SE = .005, p = .09) and diastolic (B = -.004, SE = .002, p = .08) blood pressure reactivity. Decreased intraindividual RT variability was associated with impaired systolic blood pressure recovery (B = -.007, SE = .003, p = .03) and impaired vagal tone (B = -.0047, SE = .0024, p = .045). Study findings offer tentative support for an association between RTs and CV responses. Despite small effect sizes and associations not consistent across predictors, these data may point to a link between intrinsic neuronal plasticity and CV responses.

  6. Do ewes born with a male co-twin have greater longevity with lambing over time?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Based on a recent analysis of historical records, ewes born co-twin to a ram had greater lifetime reproductive performance than ewes born co-twin to a ewe. We are interested in determining what component(s) of lifetime reproductive performance may be associated with a ewe’s co-twin sex. As an initi...

  7. FIELD EVALUATION OF A MODIFIED DATARAM MIE SCATTERING MONITOR FOR REAL-TIME PM2.5 MASS CONCENTRATION MEASUREMENTS. (R827352C005)

    EPA Science Inventory

    In this paper, we investigated the feasibility of using a modified DataRAM nephelometer (RAM-1, MIE Inc., Billerica, MA) as a continuous PM2.5 monitor to measure concentrations of ambient and concentrated aerosols in real time. The DataRAM operated with a diffusion ...

  8. Source identification of ambient PM 2.5 for inhalation exposure studies in Steubenville, Ohio using highly time-resolved measurements

    NASA Astrophysics Data System (ADS)

    Morishita, Masako; Keeler, Gerald J.; Kamal, Ali S.; Wagner, James G.; Harkema, Jack R.; Rohr, Annette C.

    2011-12-01

    Recent epidemiological and toxicological studies have suggested that short-term elevations of ambient fine particle mass concentrations (aerodynamic diameter <2.5 μm, PM 2.5) can increase cardiac and pulmonary health risks. Thus, examining temporal variations of chemical changes in ambient PM 2.5 that could pose the greatest health risks and identifying its sources is critical so that the most toxic categories can be controlled. In this study we collected detailed air quality data in Steubenville, Ohio in August 2006 with the ultimate goal to evaluate associations between cardiovascular (CV) parameters measured in exposed laboratory animals and the chemical and elemental composition of PM 2.5. Current approaches using radiotelemetry to measure CV parameters in conscious laboratory animals are capable of collecting continuous recordings. To provide a robust and analogous dataset that can be better matched with CV responses, we have incorporated a highly time-resolved sampling method to characterize trace elements and thereby obtain more robust input data to determine potential emission sources. We applied positive matrix factorization (PMF) to trace element concentrations from 30-minute ambient PM 2.5 samples in Steubenville, Ohio, an area designated as a non-attainment area for the PM 2.5 National Ambient Air Quality Standards by the Environmental Protection Agency. The average ambient PM 2.5 filter-based mass concentration during the 8-hour summer exposure study period was 26 ± 11 μg m -3. Results from PMF indicated that six major factors contributed to the ambient PM 2.5 mass during this time: coal combustion/secondary (39 ± 46%), mobile sources (12 ± 14%), metal coating/processing (10 ± 11%), iron and steel manufacturing (5 ± 5%), Pb factor (5 ± 8%), and incineration/smelting (1 ± 3%). The objectives of this paper are (1) to present chemical composition of ambient PM 2.5 and its potential emission sources in Steubenville; and (2) to evaluate the PMF

  9. Increasing Time and Enriching Learning for Greater Equity in Schools: Perspective from Two Community Funders

    ERIC Educational Resources Information Center

    Lopez, Janet; Rivera, Peter

    2015-01-01

    Foundations across the country engage in grantmaking to eliminate the opportunity and achievement gaps in K-12 public schools. Many of the strategies and investments that funders have supported in recent years focus not only on "more time" but also on "better use of time" in schools. This better use of time centers on outcomes…

  10. Web-Based Time Entry Systems: Providing Greater Automation and Compliance

    ERIC Educational Resources Information Center

    Williams, Tracy

    2005-01-01

    Time and resources are becoming increasingly scarce in most higher education institutions today. As a result, colleges and universities are looking to streamline and simplify many costly, labor-intensive administrative processes. In this article, Tracy Williams examines how Web-based time-entry systems can help institutions save valuable time and…

  11. Identification of ambient PM 2.5 sources and analysis of pollution episodes in Detroit, Michigan using highly time-resolved measurements

    NASA Astrophysics Data System (ADS)

    Morishita, Masako; Keeler, Gerald J.; Kamal, Ali S.; Wagner, James G.; Harkema, Jack R.; Rohr, Annette C.

    2011-03-01

    Recent studies have indicated that the chemical composition of ambient PM 2.5, or fine particulate matter (aerodynamic diameter <2.5 μm), may be closely associated with the health effects induced by PM. Thus, identification of the sources of these components of PM 2.5 is critical to understanding source-specific health risks posed by PM 2.5. However, ambient PM measurements are typically 24-h average concentrations, masking the temporal variability of individual sources. These daily samples can limit our understanding of the associations between sources and observed heath effect parameters. In the present study, highly time-resolved sampling methods were utilized to characterize trace element concentrations and to obtain information on potential emission sources impacting a site in urban Detroit where a complex mixture of local point and mobile sources, as well as regional sources, is observed. Positive matrix factorization (PMF) was applied to 117 8-h PM 2.5 filter samples from which six major factors were extracted including secondary aerosol, gasoline-powered vehicles, iron and steel manufacturing, diesel-powered vehicles, refining, and sludge incineration. In addition, PMF was applied to 268 30-min PM 2.5 samples where six major source factors were identified including secondary aerosol, gasoline- and diesel-powered vehicles, iron and steel manufacturing, refining, sludge incineration, and cement/lime production. Contributions of various emission source factors and peak concentrations for each factor were characterized using detailed meteorology and, factor directionality analysis. Although some variations were observed between the 8-h integrated filter samples and the 30-min SEAS samples, the results from the two datasets are generally consistent, suggesting that 46% and 43% of ambient PM, respectively, is derived from local sources. These findings have advanced our understanding of temporal PM source-receptor relationships in a complex urban air shed.

  12. Does Social Connectedness Promote a Greater Sense of Well-Being in Adolescence over Time?

    ERIC Educational Resources Information Center

    Jose, Paul E.; Ryan, Nicholas; Pryor, Jan

    2012-01-01

    This longitudinal study was designed to investigate whether or not social connectedness predicts psychological well-being over time. Structural equation modeling was used to examine the temporal relations between these constructs assessed yearly for 3 years for a sample of 1,774 10- to 15-year-olds (at Time 1). Results indicated that global…

  13. Implementing constrained multi-time approach with bootstrap analysis in ME-2: An application to PM2.5 data from Florence (Italy).

    PubMed

    Crespi, A; Bernardoni, V; Calzolai, G; Lucarelli, F; Nava, S; Valli, G; Vecchi, R

    2016-01-15

    Advanced receptor models have been recently developed and tested in order to improve the resolution of apportionment problems reducing rotational ambiguity of results and aiming at identifying a larger number of sources. In particular, multi-time model is a factor analysis method able to compute source profiles and contributions using aerosol compositional data with different time resolutions. Unlike traditional factor analysis, each measured value can be inserted into multi-time model with its original time schedule, thus all temporal information can be effectively used in the modelling process. In this work, multi-time model was expanded in order to impose constraints on modelled factors aiming at improving the source identification. Moreover, as far as we know for the first time, a suitable bootstrap technique was implemented in the multi-time scheme to estimate the uncertainty of the final constrained solutions. These implemented approaches were tested on a PM2.5 (particulate matter with aerodynamic diameter <2.5 μm) dataset composed of 24-h samples collected during one year and hourly data sampled in parallel for two shorter periods in Florence (Italy). The daily samples were chemically characterised for elements, ions and carbonaceous components while elemental concentrations only were available for high-time resolved samples. The application of the advanced model revealed the major contribution from traffic (accounting for 37% of PM2.5 as annual average) and allowed an accurate characterisation of involved emission processes. In particular, exhaust and non-exhaust emissions were identified. The constraints imposed in the continuation run led to a better description of the factor associated to nitrates and also of biomass burning profile and the bootstrap results gave useful information to assess the reliability of source apportionment solutions. Finally, the comparison with the results computed by ME-2 base model applied to daily and hourly compositional

  14. Air pollution and early deaths in the United States. Part II: Attribution of PM2.5 exposure to emissions species, time, location and sector

    NASA Astrophysics Data System (ADS)

    Dedoussi, Irene C.; Barrett, Steven R. H.

    2014-12-01

    Combustion emissions constitute the largest source of anthropogenic emissions in the US, and lead to the degradation of air quality and human health. In Part I we computed the population fine particulate matter (PM2.5) exposure and number of early deaths caused by emissions from six major sectors: electric power generation, industry, commercial and residential activities, road transportation, marine transportation and rail transportation. In Part II we attribute exposure and early deaths to sectors, emissions species, time of emission, and location of emission. We apply a long-term adjoint sensitivity analysis and calculate the four dimensional sensitivities (time and space) of PM2.5 exposure with respect to each emissions species. Epidemiological evidence is used to relate increased population exposure to premature mortalities. This is the first regional application of the adjoint sensitivity analysis method to characterize long-term air pollution exposure. (A global scale application has been undertaken related to intercontinental pollution.) We find that for the electric power generation sector 75% of the attributable PM2.5 exposure is due to SO2 emissions, and 80% of the annual impacts are attributed to emissions from April to September. In the road transportation sector, 29% of PM2.5 exposure is due to NOx emissions and 33% is from ammonia (NH3), which is a result of emissions after-treatment technologies. We estimate that the benefit of reducing NH3 emissions from road transportation is ∼20 times that of NOx per unit mass. 75% of the road transportation ammonia impacts occur during the months October to March. We publicly release the sensitivity matrices computed, noting their potential use as a rapid air quality policy assessment tool.

  15. Prolonged time to pregnancy is associated with a greater risk of adverse outcomes.

    PubMed

    Raatikainen, Kaisa; Harju, Maija; Hippeläinen, Maritta; Heinonen, Seppo

    2010-08-01

    Births with known time to pregnancy (TTP) during the period 1989-2007 (n=17,114) were analyzed to investigate associations between TTP and pregnancy outcome among couples that conceived spontaneously. The adjusted odds ratio (95% confidence interval) for poor neonatal health, including low Apgar score, low umbilical vein pH, and need for neonatal intensive care, was 1.51 (1.09-2.09) in women who had a TTP of 25-36 months and 1.60 (1.18-2.19) in women who had a TTP of >or=37 months compared with women with a TTP of 0-6 months.

  16. A CROSS-PROVINCE ANALYSIS OF URBAN AND RURAL INDOOR PM2.5 EXPOSURE IN CHINA USING TIME USE SURVEY

    NASA Astrophysics Data System (ADS)

    Shimada, Yoko; Guo, Minna; Kurata, Gakuji; Matsuoka, Yuzuru

    In developing countries in Asia and other parts of the world, most energy sources used in the home are solid fuels such as coal and biomass (firewood, crop residue and animal dung). Particulate matter 2.5, consisting of particles with an aerodynamic diameter of 2.5 um or less, produced through combustion of these fuels inside the residence for cooking and heating has an adverse impact on people's health. We estimated PM2.5 exposure concentration in indoor microenvironment for each cohort of urban and rural area in ten provinces of China, using statistical data on time use survey and domestic energy consumption. The study found that, in each province, the exposure concentration in rural area was higher than in urban area, unemployed women between the ages of 60 and 64 had the highest estimate for exposure concentration at 3027 μg/m3. The study also found that the exposure concentration for individual cohorts in each province was greatly affected by people's use of time indoors, fuel consumption such as coal or biomass and floor space.

  17. A time-series analysis of mortality and air temperature in Greater Beirut.

    PubMed

    El-Zein, Abbas; Tewtel-Salem, Mylene; Nehme, Gebran

    2004-09-01

    The literature on the association between health and weather in the temperate to semi-arid cities of the Eastern Mediterranean is scarce. The quantification of the relationship between temperature and daily mortality can be useful for developing policy interventions such as heat-warning systems. A time-series analysis of total daily mortality and weather data for the city of Beirut was carried out. The study covered the period between 1997 and 1999. Poisson auto-regressive models were constructed, with mean daily temperature and mean daily humidity as explanatory variables. Delayed effects, up to 2 weeks, were accounted for. The regression models were used next to assess the effect of an average increase in temperature on yearly mortality. The association between temperature and mortality was found to be significant. A relatively high minimum-mortality temperature (TMM) of 27.5 degrees C was calculated. A 1 degrees C rise in temperature yielded a 12.3% increase (95% confidence interval: 5.7-19.4%) and 2.9% decrease (95% confidence interval: 2-3.7%) in mortality, above and below TMM, respectively. Lag temperature variables were found to be significant below TMM but not above it. Where the temperature change was less than 0.5 degrees C, annual above-TMM losses were offset by below-TMM gains, within a 95% confidence interval. TMM for Beirut fell within the range usually associated with warm climates. However, the mild below-TMM and steep above-TMM slopes were more typical of cities with temperate to cold climates. Our findings suggest that heat-related mortality at moderately high temperatures can be a significant public health issue in countries with warm climates. Moreover, at the projected climate change over the next 50 years, heat-related losses are unlikely to be offset by cold-related gains. PMID:15325159

  18. Optical absorption spectra of boron clusters Bn (n = 2-5) for application in nano scintillator - a time dependent density functional theory study

    NASA Astrophysics Data System (ADS)

    Shivade, Rajendra K.; Chakraborty, Brahmananda

    2016-09-01

    Boron nano-clusters of various shapes and sizes have potential applications as scintillating detector and hydrogen storage material. Using time dependent density functional theory (TDDFT) as implemented in CASIDA we have studied the linear optical absorption spectra for boron clusters B n ( n = 2-5) and compared with previously reported results using Hatree-Fock (H-F) based method where the spectrum is limited to 8 eV due to exclusion of excitation into very high energy unoccupied orbital. The optical spectra fall in the visible and near UV region and are very much dependent on the shape of the isomer. We have obtained additional peaks for B2 linear, B3 triangular, B4 rhombus and square shaped isomers beyond 8 eV which were missing in the previous H-F based study and has significance as they fall below the ionization potential. We correlate the optical spectrum with the shape of the Kohn-Sham orbitals and HUMO-LUMO gap and assess comparative stability of various B n ( n = 2-5) clusters in terms of HUMO-LUMO gap, bond-length and relative energy. TDDFT computed optical spectroscopy correlated with Kohn-Sham orbitals and HUMO-LUMO gap and its comparison with H-F based method may give significant knowledge regarding geometry and optical properties of B n ( n = 2-5) clusters enabling to distingush between various isomers of B n clusters.

  19. Time-Resolved Gas-Phase Kinetic, Quantum Chemical, and RRKM Studies of the Reaction of Silylene with 2,5-Dihydrofuran.

    PubMed

    Becerra, Rosa; Cannady, J Pat; Pfrang, Christian; Walsh, Robin

    2015-11-19

    Time-resolved kinetics studies of silylene, SiH2, generated by laser flash photolysis of phenylsilane, were performed to obtain rate coefficients for its bimolecular reaction with 2,5-dihydrofuran (2,5-DHF). The reaction was studied in the gas phase over the pressure range of 1-100 Torr in SF6 bath gas, at five temperatures in the range of 296-598 K. The reaction showed pressure dependences characteristic of a third body assisted association. The second-order rate coefficients obtained by Rice-Ramsperger-Kassel-Marcus (RRKM)-assisted extrapolation to the high-pressure limit at each temperature fitted the following Arrhenius equation where the error limits are single standard deviations: log(k/cm(3) molecule(-1) s(-1)) = (-9.96 ± 0.08) + (3.38 ± 0.62 kJ mol(-1))/RT ln 10. End-product analysis revealed no GC-identifiable product. Quantum chemical (ab initio) calculations indicate that reaction of SiH2 with 2,5-DHF can occur at both the double bond (to form a silirane) and the O atom (to form a donor-acceptor, zwitterionic complex) via barrierless processes. Further possible reaction steps were explored, of which the only viable one appears to be decomposition of the O-complex to give 1,3-butadiene + silanone, although isomerization of the silirane cannot be completely ruled out. The potential energy surface for SiH2 + 2,5-DHF is consistent with that of SiH2 with Me2O, and with that of SiH2 with cis-but-2-ene, the simplest reference reactions. RRKM calculations incorporating reaction at both π- and O atom sites, can be made to fit the experimental rate coefficient pressure dependence curves at 296-476 K, giving values for k(∞)(π) and k(∞)(O) that indicate the latter is larger in magnitude at all temperatures, in contrast to values from individual model reactions. This unexpected result suggests that, in 2,5-DHF with its two different reaction sites, the O atom exerts the more pronounced electrophilic attraction on the approaching silylene. Arrhenius parameters

  20. Stochastic univariate and multivariate time series analysis of PM2.5 and PM10 air pollution: A comparative case study for Plovdiv and Asenovgrad, Bulgaria

    NASA Astrophysics Data System (ADS)

    Gocheva-Ilieva, S.; Stoimenova, M.; Ivanov, A.; Voynikova, D.; Iliev, I.

    2016-10-01

    Fine particulate matter PM2.5 and PM10 air pollutants are a serious problem in many urban areas affecting both the health of the population and the environment as a whole. The availability of large data arrays for the levels of these pollutants makes it possible to perform statistical analysis, to obtain relevant information, and to find patterns within the data. Research in this field is particularly topical for a number of Bulgarian cities, European country, where in recent years regulatory air pollution health limits are constantly being exceeded. This paper examines average daily data for air pollution with PM2.5 and PM10, collected by 3 monitoring stations in the cities of Plovdiv and Asenovgrad between 2011 and 2016. The goal is to find and analyze actual relationships in data time series, to build adequate mathematical models, and to develop short-term forecasts. Modeling is carried out by stochastic univariate and multivariate time series analysis, based on Box-Jenkins methodology. The best models are selected following initial transformation of the data and using a set of standard and robust statistical criteria. The Mathematica and SPSS software were used to perform calculations. This examination showed measured concentrations of PM2.5 and PM10 in the region of Plovdiv and Asenovgrad regularly exceed permissible European and national health and safety thresholds. We obtained adequate stochastic models with high statistical fit with the data and good quality forecasting when compared against actual measurements. The mathematical approach applied provides an independent alternative to standard official monitoring and control means for air pollution in urban areas.

  1. Correlating MODIS aerosol optical thickness data with ground-based PM 2.5 observations across Texas for use in a real-time air quality prediction system

    NASA Astrophysics Data System (ADS)

    Hutchison, Keith D.; Smith, Solar; Faruqui, Shazia J.

    Investigations have been conducted at the Center for Space Research (CSR) into approaches to correlate MODIS aerosol optical thickness (AOT) values with ground-based, PM 2.5 observations made at continuous air monitoring station locations operated by the Texas Commission on Environmental Quality (TCEQ). These correlations are needed to more fully utilize real-time MODIS AOT analyses generated at CSR in operational air quality forecasts issued by TCEQ using a trajectory-based forecast model developed by NASA. Initial analyses of two data sets collected during 3 months in 2003 and all of 2004 showed linear correlations in the 0.4-0.5 range in the data collected over Texas. Stronger correlations (exceeding 0.9) were obtained by averaging these same data over longer timescales but this approach is considered unsuitable for use in issuing air quality forecasts. Peculiarities in the MODIS AOT analyses, referred to as hot spots, were recognized while attempting to improve these correlations. It is demonstrated that hot spots are possible when pixels that contain surface water are not detected and removed from the AOT retrieval algorithms. An approach to reduce the frequency of hot spots in AOT analyses over Texas is demonstrated by tuning thresholds used to detect inland water surfaces and remove pixels that contain them from the analysis. Finally, the potential impact of hot spots on MODIS AOT-PM 2.5 correlations is examined through the analysis of a third data set that contained sufficient levels of aerosols to mask inland water surfaces from the AOT algorithms. In this case, significantly stronger correlations, that exceed the 0.9 value considered suitable for use in a real-time air quality prediction system, were observed between the MODIS AOT observations and ground-based PM 2.5 measurements.

  2. Time-dependent neuromuscular parameters in the plantar flexors support greater fatigability of old compared with younger males.

    PubMed

    Wallace, Jonathan W; Power, Geoffrey A; Rice, Charles L; Dalton, Brian H

    2016-02-01

    Older adults are more fatigable than young during dynamic tasks, especially those that involve moderate to fast unconstrained velocity shortening contractions. Rate of torque development (RTD), rate of velocity development (RVD) and rate of neuromuscular activation are time-dependent neuromuscular parameters which have not been explored in relation to age-related differences in fatigability. The purpose was to determine whether these time-dependent measures affect the greater age-related fatigability in peak power during moderately fast and maximal effort shortening plantar flexions. Neuromuscular properties were recorded from 10 old (~ 78 years) and 10 young (~ 24 years) men during 50 maximal-effort unconstrained velocity shortening plantar flexions against a resistance equivalent to 20% maximal voluntary isometric contraction torque. At task termination, peak power, and angular velocity, and torque at peak power were decreased by 30, 18, and 16%, respectively, for the young (p < 0.05), and 46, 28, 30% for the old (p < 0.05) compared to pre-fatigue values with the old exhibiting greater reductions across all measures (p<0.05). Voluntary RVD and RTD decreased, respectively, by 24 and 26% in the young and by 47 and 40% in the old at task termination, with greater decrements in the old (p < 0.05). Rate of neuromuscular activation of the soleus decreased over time for both age groups (~ 47%; p < 0.05), but for the medial gastrocnemius (MG) only the old experienced significant decrements (46%) by task termination. All parameters were correlated strongly with the fatigue-related reduction in peak power (r = 0.81-0.94, p < 0.05), except for MG and soleus rates of neuromuscular activation (r = 0.25-0.30, p > 0.10). Fatigue-related declines in voluntary RTD and RVD were both moderately correlated with MG rate of neuromuscular activation (r = 0.51-0.52, p < 0.05), but exhibited a trend with soleus (r = 0.39-0.41, p = 0.07-0.09). Thus, time-dependent factors, RVD and RTD

  3. Oman-India pipeline sets survey challenges. Crossing involves most rugged terrain, water depths four times greater than previous attempts

    SciTech Connect

    Flynn, J.

    1995-02-01

    Decisions concerning the route for the world`s deepest pipeline call for some of the most challenging commercial oceanographic and engineering surveys ever undertaken. Oman Oil Co.`s 1, 170-kilometer pipeline will carry 2 billion cubic feet of gas daily across the Arabian Sea from Oman to the northern coast of India at the Gulf of Kutch. Not only will the project be in water depths four times greater than any previous pipeline, but it will cross some of the world`s most rugged seabed terrain, traversing ridges and plunging into deep canyons. Project costs are likely to approach $5 billion.

  4. Air quality forecasting for winter-time PM2.5 episodes occurring in multiple cities in central and southern Chile

    NASA Astrophysics Data System (ADS)

    Saide, Pablo E.; Mena-Carrasco, Marcelo; Tolvett, Sebastian; Hernandez, Pablo; Carmichael, Gregory R.

    2016-01-01

    Episodic air quality degradation due to particles occurs in multiple cities in central and southern Chile during the austral winter reaching levels up to 300-800 µg/m3 hourly PM2.5, which can be associated with severe effects on human health. An air quality prediction system is developed to predict such events in near real time up to 3 days in advance for nine cities with regular air quality monitoring: Santiago, Rancagua, Curicó, Talca, Chillan, Los Ángeles, Temuco, Valdivia, and Osorno. The system uses the Weather Research and Forecasting with Chemistry model configured with a nested 2 km grid-spacing domain to predict weather and inert tracers. The tracers are converted to hourly PM2.5 concentrations using an observationally based calibration which is substantially less computationally intensive than a full chemistry model. The conversion takes into account processes occurring in these cities, including higher likelihood of episode occurrence during weekends and during colder days, the latter related to increased wood-burning-stove activity for heating. The system is calibrated and evaluated for April-August 2014 where it has an overall skill of 53-72% of episodes accurately forecasted (61-76% for the best initialization) which is better than persistence for most stations. Forecasts one, two, and three days in advance all have skill in forecasting events but often present large variability within them due to different meteorological initializations. The system is being implemented in Chile to assist authority decisions not only to warn the population but also to take contingency-based emission restrictions to try to avoid severe pollution events.

  5. Chemical composition of PM10 and PM2.5 collected at ground level and 100 meters during a strong winter-time pollution episode in Xi'an, China.

    PubMed

    Shen, Zhenxing; Cao, Junji; Liu, Suixin; Zhu, Chongshu; Wang, Xin; Zhang, Ting; Xu, Hongmei; Hu, Tafeng

    2011-11-01

    An intensive sampling of aerosol particles from ground level and 100 m was conducted during a strong pollution episode during the winter in Xi'an, China. Concentrations of water-soluble inorganic ions, carbonaceous compounds, and trace elements were determined to compare the composition of particulate matter (PM) at the two heights. PM mass concentrations were high at both stations: PM10 (PM with aerodynamic diameter < or =10 microm) exceeded the China National Air Quality Standard Class II value on three occasions, and PM2.5 (PM with aerodynamic diameter < or =2.5 microm) exceeded the daily U.S. National Ambient Air Quality Standard more than 10 times. The PM10 organic carbon (OC) and elemental carbon (EC) were slightly lower at the ground than at 100 m, both in terms of concentration and percentage of total mass, but OC and EC in PM2.5 exhibited the opposite pattern. Major ionic species, such as sulfate and nitrate, showed vertical variations similar to the carbonaceous aerosols. High sulfate concentrations indicated that coal combustion dominated the PM mass both at the ground and 100 m. Correlations between K+ and OC and EC at 100 m imply a strong influence from suburban biomass burning, whereas coal combustion and motor vehicle exhaust had a greater influence on the ground PM. Stable atmospheric conditions apparently led to the accumulation of PM, especially at 100 m, and these conditions contributed to the similarities in PM at the two elevations. Low coefficient of divergence (CD) values reflect the similarities in the composition of the aerosol between sites, but higher CDs for fine particles compared with coarse ones were consistent with the differences in emission sources between the ground and 100 m.

  6. Rapid gut transit time and slow fecal isoflavone disappearance phenotype are associated with greater genistein bioavailability in women.

    PubMed

    Zheng, Yan; Hu, Jiang; Murphy, Patricia A; Alekel, D Lee; Franke, Warren D; Hendrich, Suzanne

    2003-10-01

    The bioavailability of soybean isoflavones varies widely among individuals due to many factors, including activities of gut microflora. To characterize factors that affect fecal isoflavone disappearance phenotype and isoflavone bioavailability in women, 35 Asian and 33 Caucasian women, 18-43 y of age, provided fecal samples for anaerobic incubation with isoflavones in vitro at two times 5 mo apart (Phases I and II). Diet, physical activity and health history were investigated at these times. A single dose of soymilk powder [1.2 mg (4.57 micromol) total isoflavone/kg body] was given to all subjects with breakfast in phase II. Daidzein and genistein from fecal incubations, urine and fecal samples were measured by reverse-phase HPLC. Three significantly different daidzein and two genistein disappearance phenotypes were identified from fecal isoflavone incubations. More Asians than Caucasians were identified within the high daidzein disappearance phenotype. Caucasians and Asians differed significantly in daily intake of red meat (0.3 +/- 0.1 vs. 1.0 +/- 0.1 servings/d), dairy foods (2.9 +/- 0.2 vs. 1.2 +/- 0.2 servings/d) and insoluble dietary fiber (3.6 +/- 0.3 vs. 1.4 +/- 0.3 g). BMI, maximal oxygen uptake (VO(2 max)) and physical activity level were significantly greater in Caucasians than in Asians. Asian subjects of the low genistein disappearance phenotype had more rapid gut transit time (GTT) and greater isoflavone bioavailability as reflected in urinary genistein excretion than did Asians of the high genistein disappearance phenotype (GTT, 40 +/- 8 vs. 63 +/- 5 h; 11.0 +/- 2.7 vs. 4.0 +/- 1.7% of ingested genistein excreted in urine). Caucasians of both genistein disappearance phenotypes had longer GTT than did Asian subjects (84 +/- 5 vs. 56 +/- 6 h) and resembled Asians of the high genistein disappearance phenotype in genistein bioavailability. Relatively rapid GTT coupled with a low fecal isoflavone disappearance phenotype as occurred in Asian but not

  7. PM 2.5 characterization for time series studies: Organic molecular marker speciation methods and observations from daily measurements in Denver

    NASA Astrophysics Data System (ADS)

    Dutton, Steven J.; Williams, Daniel E.; Garcia, Jessica K.; Vedal, Sverre; Hannigan, Michael P.

    Particulate matter less than 2.5 microns in diameter (PM 2.5) has been shown to have a wide range of adverse health effects and consequently is regulated in accordance with the US-EPA's National Ambient Air Quality Standards. PM 2.5 originates from multiple primary sources and is also formed through secondary processes in the atmosphere. It is plausible that some sources form PM 2.5 that is more toxic than PM 2.5 from other sources. Identifying the responsible sources could provide insight into the biological mechanisms causing the observed health effects and provide a more efficient approach to regulation. This is the goal of the Denver Aerosol Sources and Health (DASH) study, a multi-year PM 2.5 source apportionment and health study. The first step in apportioning the PM 2.5 to different sources is to determine the chemical make-up of the PM 2.5. This paper presents the methodology used during the DASH study for organic speciation of PM 2.5. Specifically, methods are covered for solvent extraction of non-polar and semi-polar organic molecular markers using gas chromatography-mass spectrometry (GC-MS). Vast reductions in detection limits were obtained through the use of a programmable temperature vaporization (PTV) inlet along with other method improvements. Results are presented for the first 1.5 years of the DASH study revealing seasonal and source-related patterns in the molecular markers and their long-term correlation structure. Preliminary analysis suggests that point sources are not a significant contributor to the organic molecular markers measured at our receptor site. Several motor vehicle emission markers help identify a gasoline/diesel split in the ambient data. Findings show both similarities and differences when compared with other cities where similar measurements and assessments have been made.

  8. PM2.5 Characterization for Time Series Studies: Organic Molecular Marker Speciation Methods and Observations from Daily Measurements in Denver

    PubMed Central

    Dutton, Steven J.; Williams, Daniel E.; Garcia, Jessica K.; Vedal, Sverre; Hannigan, Michael P.

    2009-01-01

    Particulate matter less than 2.5 microns in diameter (PM2.5) has been shown to have a wide range of adverse health effects and consequently is regulated in accordance with the US-EPA’s National Ambient Air Quality Standards. PM2.5 originates from multiple primary sources and is also formed through secondary processes in the atmosphere. It is plausible that some sources form PM2.5 that is more toxic than PM2.5 from other sources. Identifying the responsible sources could provide insight into the biological mechanisms causing the observed health effects and provide a more efficient approach to regulation. This is the goal of the Denver Aerosol Sources and Health (DASH) study, a multi-year PM2.5 source apportionment and health study. The first step in apportioning the PM2.5 to different sources is to determine the chemical make-up of the PM2.5. This paper presents the methodology used during the DASH study for organic speciation of PM2.5. Specifically, methods are covered for solvent extraction of non-polar and semi-polar organic molecular markers using gas chromatography-mass spectrometry (GC-MS). Vast reductions in detection limits were obtained through the use of a programmable temperature vaporization (PTV) inlet along with other method improvements. Results are presented for the first 1.5 years of the DASH study revealing seasonal and source-related patterns in the molecular markers and their long-term correlation structure. Preliminary analysis suggests that point sources are not a significant contributor to the organic molecular markers measured at our receptor site. Several motor vehicle emission markers help identify a gasoline/diesel split in the ambient data. Findings show both similarities and differences when compared with other cities where similar measurements and assessments have been made. PMID:20161318

  9. Observational evidence that massive cluster galaxies were forming stars at z ~ 2.5 and did not grow in mass at later times

    NASA Astrophysics Data System (ADS)

    Andreon, S.

    2013-06-01

    Using Spitzer 3.6 micron data we derived the luminosity function and the mass function of galaxies in five z > 1.4 clusters selected to have a firm intracluster medium detection. The five clusters differ in richness (ISCS J1438.1+3414 and XMMXCS J2215.9-1738 are twice as rich as ISCS J1432.4+3250, IDCS J1426.5+3508, and JKCS 041) and morphological appareance. At the median redshift z = 1.5, from the 150 member galaxies of the five clusters, we derived a characteristic magnitude of 16.92 ± 0.13 in the [3.6] band and a characteristic mass of lg M∗ = 11.30 ± 0.05 M⊙. We find that the characteristic luminosity and mass does not evolve between z = 1 and 1.4 < z < 1.8, directly ruling out ongoing mass assembly between these epochs because massive galaxies are already present up to z = 1.8. Lower-redshift build-up epochs have already been ruled out by previous works, leaving only z > 1.8 as a possible epoch for the mass build up. However, the observed values of m∗ at very high redshift are too bright for galaxies without any star formation immediately preceding the observed redshift and therefore imply a star formation episode not earlier than zf = 2.5. For the first time, mass/luminosity functions are able to robustly distinguish tiny differences between formation redshifts and to set upper limits to the epoch of the last star-formation episode.

  10. Comparative study using oral solutions of bambuterol once daily or terbutaline three times daily in 2-5-year-old children with asthma. Bambuterol Multicentre Study Group.

    PubMed

    Kuusela, A L; Marenk, M; Sandahl, G; Sanderud, J; Nikolajev, K; Persson, B

    2000-03-01

    The aim of this study was to compare safety and efficacy of bambuterol hydrochloride (10 mg) oral solution administered once daily in the evening with terbutaline sulphate (0.075 mg/kg body weight) oral solution administered three times daily in 2-5-year-old children with asthma. There were two treatment groups: (2/3) of the patients received bambuterol and (1/3) received terbutaline. The study was double-blind, randomized, and of a parallel group design, and it lasted for 3 months after a 2-week run-in period. The primary objective was to evaluate safety (adverse events, and changes in blood pressure, pulse rate, hematology, and clinical chemistry parameters). Plasma concentrations of terbutaline and/or bambuterol were also measured. Evaluation of efficacy (diary card data) was a secondary objective. A total of 155 patients (range, 2-6 years; 3 patients were 6 years old at randomization) were treated with the study drugs; 104 patients received bambuterol and 51 patients received terbutaline. Both treatments showed a good safety profile with respect to clinical and laboratory tests, and they were generally well tolerated. Reported adverse events were mild to moderate. There were no statistically significant differences between treatment groups in any of the efficacy variables (diary variables: peak expiratory flow (PEF), asthma symptoms, restlessness, other reported symptoms, use of inhaled bronchodilators, and nighttime awakenings). For morning PEF, the mean increase from run-in to treatment was 16.9 L/min in the terbutaline group and 23.3 L/min in the bambuterol group. For evening PEF, the mean increase was 20.2 L/min in the terbutaline group and 20.6 L/min in the bambuterol group. In conclusion, once-daily bambuterol is as safe and effective as terbutaline given three times daily. The study also confirmed that bambuterol has a 24-hr duration of action, and therefore its once daily administration, makes it a preferred bronchodilator agent. Pediatr Pulmonol. 2000

  11. Low precipitation events in the European Greater Alpine Region and their space-time patterns in the past 210 years.

    NASA Astrophysics Data System (ADS)

    Haslinger, Klaus; Holawe, Franz; Blöschl, Günter

    2016-04-01

    In this study space-time patterns of low precipitation events in the Greater Alpine Region (GAR) of Europe are investigated. A long term gridded dataset of monthly precipitation sums spanning the last 210 years is used to assess abnormally dry states by applying a monthly percentile deceedence threshold. Furthermore, these anomalies are calculated for 1, 3, 6 and 12 months moving averages. Contiguous areas of grid points below the threshold are recorded in a lookup table in order to assess the dry anomalies on an event-based approach. The overall event severity is determined by the mean deviation from the threshold level and the area affected. With this approach we are able to show that the most severe dry anomalies take place in the 1860s, 1850s and 1940s, although there are some differences in the occurrence over time in summer and winter. Winter dry anomalies are more frequent in the 19th century, whereas in summer no clear patterns are perceptible. A spatial clustering analysis of the anomaly fields also reveals distinct patterns in space, clearly indicating the Main Alpine Crest as a major divide of dry anomalies from North to South. A joint consideration of detected dry anomaly events and their associated temperature anomalies shows that in winter of the late 19th and early 20th century dry conditions are more often accompanied by cold temperatures in contrast to the last 50 years where dry anomalies are associated with above average winter temperatures. In general dry summers are more likely warmer than the long term mean, but there is also a considerable number of dry events with negative temperature anomalies, particularly in the late 19th and early 20th century.

  12. INTERCOMPARISON OF NEAR REAL-TIME MONITORS OF PM2.5 NITRATE AND SULFATE AT THE U.S. ENVIRONMENTAL PROTECTION AGENCY ATLANTA SUPERSITE

    EPA Science Inventory

    Five new instruments for semi-continuous measurements of fine particle (PM2.5) nitrate and sulfate were deployed at the Atlanta Supersite Experiment during an intensive study in August 1999. The instruments measured bulk aerosol chemical composition at rates ranging from every...

  13. Characterization of PM2.5, gaseous pollutants, and meteorological interactions in the context of time-series health effects models.

    PubMed

    Ito, Kazuhiko; Thurston, George D; Silverman, Robert A

    2007-12-01

    Associations of particulate matter (PM) and ozone with morbidity and mortality have been reported in many recent observational epidemiology studies. These studies often considered other gaseous co-pollutants also as potential confounders, including nitrogen dioxide (NO2), sulfur dioxide (SO2), and carbon monoxide (CO). However, because each of these air pollutants can have different seasonal patterns and chemical interactions, the estimation and interpretation of each pollutant's individual risk estimates may not be straightforward. Multi-collinearity among the air pollution and weather variables also leaves the possibility of confounding and over- or under-fitting of meteorological variables, thereby potentially influencing the health effect estimates for the various pollutants in differing ways. To investigate these issues, we examined the temporal relationships among air pollution and weather variables in the context of air pollution health effects models. We compiled daily data for PM less than 2.5 mum (PM2.5), ozone, NO2, SO2, CO, temperature, dew point, relative humidity, wind speed, and barometric pressure for New York City for the years 1999-2002. We conducted several sets of analyses to characterize air pollution and weather data interactions, to assess different aspects of these data issues: (1) spatial/temporal variation of PM2.5 and gaseous pollutants measured at multiple monitors; (2) temporal relationships among air pollution and weather variables; and (3) extent and nature of multi-collinearity of air pollution and weather variables in the context of health effects models. The air pollution variables showed a varying extent of intercorrelations with each other and with weather variables, and these correlations also varied across seasons. For example, NO2 exhibited the strongest negative correlation with wind speed among the pollutants considered, while ozone's correlation with PM2.5 changed signs across the seasons (positive in summer and negative in

  14. Identifying Optimal Temporal Scale for the Correlation of AOD and Ground Measurements of PM2.5 to Improve the Modeling Performance in a Real-Time Air Quality Estimation System

    NASA Technical Reports Server (NTRS)

    Li,Hui; Faruque, Fazlay; Williams, Worth; Al-Hamdan, Mohammad; Luvall, Jeffrey; Crosson, William; Rickman, Douglas; Limaye, Ashutosh

    2008-01-01

    Aerosol optical depth (AOD), derived from satellite measurements using Moderate Resolution Imaging Spectrometer (MODIS), offers indirect estimates of particle matter. Research shows a significant positive correlation between satellite-based measurements of AOD and ground-based measurements of particulate matter with aerodynamic diameter less than or equal to 2.5 micrometers (PM2.5). In addition, satellite observations have also shown great promise in improving estimates of PM2.5 air quality surface. Research shows that correlations between AOD and ground PM2.5 are affected by a combination of many factors such as inherent characteristics of satellite observations, terrain, cloud cover, height of the mixing layer, and weather conditions, and thus might vary widely in different regions, different seasons, and even different days in a same location. Analysis of correlating AOD with ground measured PM2.5 on a day-to-day basis suggests the temporal scale, a number of immediate latest days for a given run's day, for their correlations needs to be considered to improve air quality surface estimates, especially when satellite observations are used in a real-time pollution system. The second reason is that correlation coefficients between AOD and ground PM2.5 cannot be predetermined and needs to be calculated for each day's run for a real-time system because the coefficients can vary over space and time. Few studies have been conducted to explore the optimal way to apply AOD data to improve model accuracies of PM2.5 surface estimation in a real-time air quality system. This paper discusses the best temporal scale to calculate the correlation of AOD and ground particle matter data to improve the results of pollution models in real-time system.

  15. Effect of Reflow Time on Wetting Behavior, Microstructure Evolution, and Joint Strength of Sn-2.5Ag-0.5Cu Solder on Bare and Nickel-Coated Copper Substrates

    NASA Astrophysics Data System (ADS)

    Sona, Mrunali; Prabhu, K. Narayan

    2016-07-01

    The effect of reflow time on wetting behavior of Sn-2.5Ag-0.5Cu lead-free solder on bare and nickel-coated copper substrates has been investigated. The solder alloy was reflowed at 270°C for various reflow times of 10 s, 100 s, 300 s, and 500 s. On bare copper substrate, the intermetallic compound (IMC) thickness increased with increase in reflow time, whereas on Ni-coated Cu substrate, the IMC thickness increased up to 300 s followed by a drop for solder alloy reflowed for 500 s. The spreading behavior of the solder alloy was categorized into capillary, gravity (diffusion), and viscous zones. Gravity zone was obtained from 3.8 ± 0.43 s to 38.97 ± 3.38 s and from 5.99 ± 0.5 s to 77.82 ± 8.84 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. Sn-2.5Ag-0.5Cu solder alloy was also reflowed for the period corresponding to the end of the gravity zone (40 s and 80 s on bare and Ni-coated Cu, respectively). The joint strength was maximum at reflow time of 40 s and 80 s for the Sn-2.5Ag-0.5Cu/Cu and Sn-2.5Ag-0.5Cu/Ni/Cu system, respectively. The dynamic contact angle at the end of the gravity (diffusion) zone ( θ gz) was found to be a better parameter compared with the stabilized contact angle ( θ f) to assess the effect of the wettability of the liquid solder on the microstructure and joint strength. The present investigation reveals the significance of the gravity zone in assessment of optimum reflow time for lead-free solder alloys.

  16. Real-time earthquake alert system for the greater San Francisco Bay Area: a prototype design to address operational issues

    SciTech Connect

    Harben, P.E.; Jarpe, S.; Hunter, S.

    1996-05-29

    This paper describes a prototype for this EAS (real time) in the Bay area. Approach is pragmatic, attempting to establish a prototype system at a low cost and quickly. A real-time warning system can protect the public and mitigate earthquake damage. The proposed system is a distributed network of real-time strong-motion monitoring stations that telemetered data in real time to a central analysis facility which could transmit earthquake parameter information to an area before elastic wave energy arrived. Upgrades and issues that should be resolved before an operational EAS can be established, are listed.

  17. Testing Age-Paced Parenting Newsletters up to Age 3: Greater Impact on First-Time Parents

    ERIC Educational Resources Information Center

    Ostergren, Carol S.; Riley, David A.

    2012-01-01

    An age-paced newsletter for parents of toddlers was evaluated. Mothers reported the newsletters were as useful as information from doctors or nurses and more useful than other sources of information. We hypothesized and found that first-time mothers reported the newsletters more useful than experienced mothers--reading more of the newsletters and…

  18. Real-time earthquake alert system for the greater San Francisco Bay Area: a prototype design to address operational issues

    SciTech Connect

    Harben, P.E.; Jarpe, S.; Hunter, S.

    1996-12-10

    The purpose of the earthquake alert system (EAS) is to outrun the seismic energy released in a large earthquake using a geographically distributed network of strong motion sensors that telemeter data to a rapid CPU-processing station, which then issues an area-wide warning to a region before strong motion will occur. The warning times involved are short, from 0 to 30 seconds or so; consequently, most responses must be automated. The San Francisco Bay Area is particularly well suited for an EAS because (1) large earthquakes have relatively shallow hypocenters (10- to 20-kilometer depth), giving favorable ray-path geometries for larger warning times than deeper from earthquakes, and (2) the active faults are few in number and well characterized, which means far fewer geographically distributed strong motion sensors are (about 50 in this region). An EAS prototype is being implemented in the San Francisco Bay Area. The system consists of four distinct subsystems: (1) a distributed strong motion seismic network, (2) a central processing station, (3) a warning communications system and (4) user receiver and response systems. We have designed a simple, reliable, and inexpensive strong motion monitoring station that consists of a three-component Analog Devices ADXLO5 accelerometer sensing unit, a vertical component weak motion sensor for system testing, a 16-bit digitizer with multiplexing, and communication output ports for RS232 modem or radio telemetry. The unit is battery-powered and will be sited in fire stations. The prototype central computer analysis system consists of a PC dam-acquisition platform that pipes the incoming strong motion data via Ethernet to Unix-based workstations for dam processing. Simple real-time algorithms, particularly for magnitude estimation, are implemented to give estimates of the time since the earthquake`s onset its hypocenter location, its magnitude, and the reliability of the estimate. These parameters are calculated and transmitted

  19. Role-Playing and Real-Time Strategy Games Associated with Greater Probability of Internet Gaming Disorder.

    PubMed

    Eichenbaum, Adam; Kattner, Florian; Bradford, Daniel; Gentile, Douglas A; Green, C Shawn

    2015-08-01

    Research indicates that a small subset of those who routinely play video games show signs of pathological habits, with side effects ranging from mild (e.g., being late) to quite severe (e.g., losing a job). However, it is still not clear whether individual types, or genres, of games are most strongly associated with Internet gaming disorder (IGD). A sample of 4,744 University of Wisconsin-Madison undergraduates (Mage=18.9 years; SD=1.9 years; 60.5% female) completed questionnaires on general video game playing habits and on symptoms of IGD. Consistent with previous reports: 5.9-10.8% (depending on classification criteria) of individuals who played video games show signs of pathological play. Furthermore, real-time strategy and role-playing video games were more strongly associated with pathological play, compared with action and other games (e.g., phone games). The current investigation adds support to the idea that not all video games are equal. Instead, certain genres of video games, specifically real-time strategy and role-playing/fantasy games, are disproportionately associated with IGD symptoms.

  20. Role-Playing and Real-Time Strategy Games Associated with Greater Probability of Internet Gaming Disorder.

    PubMed

    Eichenbaum, Adam; Kattner, Florian; Bradford, Daniel; Gentile, Douglas A; Green, C Shawn

    2015-08-01

    Research indicates that a small subset of those who routinely play video games show signs of pathological habits, with side effects ranging from mild (e.g., being late) to quite severe (e.g., losing a job). However, it is still not clear whether individual types, or genres, of games are most strongly associated with Internet gaming disorder (IGD). A sample of 4,744 University of Wisconsin-Madison undergraduates (Mage=18.9 years; SD=1.9 years; 60.5% female) completed questionnaires on general video game playing habits and on symptoms of IGD. Consistent with previous reports: 5.9-10.8% (depending on classification criteria) of individuals who played video games show signs of pathological play. Furthermore, real-time strategy and role-playing video games were more strongly associated with pathological play, compared with action and other games (e.g., phone games). The current investigation adds support to the idea that not all video games are equal. Instead, certain genres of video games, specifically real-time strategy and role-playing/fantasy games, are disproportionately associated with IGD symptoms. PMID:26252934

  1. Constraining the Sahara freshwater discharge during sapropel S5 time by a stable isotope record from the Greater Sirte

    NASA Astrophysics Data System (ADS)

    Zirks, Eleen; Kucera, Michal; Bachem, Paul; Schulz, Hartmut

    2016-04-01

    The Nile River and the Black Sea were long considered as the only significant eastern Mediterranean freshwater sources and therefore inferred as the primary agents promoting surface stratification associated with sapropel formation. Sapropel S5, deposited during the last interglacial, marks a time of possible movement of Homo sapiens out of Africa. Satellite images revealed the existence of ancient rivers that once ran through the Sahara desert and drained into the Gulf of Sirte. Anomalous Nd isotope records from sapropel S5 deposits indicate that these rivers may have been active during MIS 5e, implying another freshwater source into the eastern Mediterranean Sea during that period. To constrain the extent of freshwater discharge into the Mediterranean from the Kufrah River during MIS 5e, a new δ18O record of five planktonic foraminifera species was generated from sediment core GeoTü SL 96, located proximal to the assumed outflow of the Kufrah River. The record from core GeoTü SL 96 compared with seven other records from the eastern Mediterranean Sea reveal a pattern of oxygen isotope anomalies which implies that the Kufrah River delivered detectable amount of freshwater during the second part of sapropel S5. These results reinforce the hypothesis that Sahara river systems were active during MIS 5e, which has ramifications for the understanding of sapropel events, reconstruction of coastal landscape, and the better understanding of migration routes of early humans.

  2. Evaluation of the Sequential Spot Sampler (S3) for time-resolved measurement of PM2.5 sulfate and nitrate through lab and field measurements

    NASA Astrophysics Data System (ADS)

    Hecobian, A.; Evanoski-Cole, A.; Eiguren-Fernandez, A.; Sullivan, A. P.; Lewis, G. S.; Hering, S. V.; Collett, J. L., Jr.

    2016-02-01

    The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time-resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ˜ 1 mm diameter dry spot at the end of the growth tube in a 100 µL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process, and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that poly ether ether ketone (PEEK) used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. The limit of detection was 0.5 µg m-3 for sulfate and 0.2 µg m-3 for nitrate for a 1 h sampling period. In a month-long field study conducted in southern California, two S3s were deployed alongside a URG denuder-filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement, with r2 = 0.99 and slope = 0.99 (±0.004) µg m-3 for sulfate and r2 = 0.99 and slope = 1.0 (±0.006) µg m-3 for nitrate. When compared to the URG denuder-filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded

  3. Evaluation of a Sequential Spot Sampler (S3) for time-resolved measurement of PM2.5 sulfate and nitrate through lab and field measurements

    NASA Astrophysics Data System (ADS)

    Hecobian, A.; Evanoski-Cole, A.; Eiguren-Fernandez, A.; Sullivan, A. P.; Lewis, G. S.; Hering, S. V.; Collett, J. L., Jr.

    2015-10-01

    The Sequential Spot Sampler (S3), a newly developed instrument to collect aerosols for time resolved chemical composition measurements, was evaluated in the laboratory and field for the measurement of particulate sulfate and nitrate. The S3 uses a multi-temperature condensation growth tube to grow individual aerosols to droplets which are then deposited as a ~ 1 mm diameter dry spot at the end of the growth tube on a 100 μL well of a multi-well plate. The well plate advances automatically to provide a sequence of time-resolved samples. The collected aerosols are subsequently analyzed in the laboratory. The sample is concentrated during the collection process and the laboratory extraction and analysis steps can be automated. The well plate, as received from the field, is placed onto a needle-based autosampler that adds liquid for sample extraction and injects sample extract from each well onto an ion chromatograph for analysis. Laboratory evaluation for sulfate and nitrate ions showed that PEEK used as well plate material does not contribute any artifacts; a 60 min extraction procedure leads to the recovery of sulfate and nitrate from the dry spots at above 95 % extraction efficiency; and samples stored frozen and analyzed up to 23 months later show less than a 10 % change in sulfate and nitrate concentrations. In a month long field study conducted in Southern California, two S3s were deployed alongside a URG denuder/filter-pack and a Particle-Into-Liquid Sampler combined with an Ion Chromatograph (PILS-IC). Collocated S3 sampler concentrations compared by linear regression show good agreement with r2 = 0.99 and slope = 0.99 (±0.004) μg m-3 for sulfate and r2 = 0.99 and slope =1.0 (±0.006) μg m-3 for nitrate. When compared to the URG denuder/filter-pack and the PILS-IC, the S3 sulfate and nitrate concentrations yielded correlations above 0.84 for the square of the correlation coefficient and regression slopes close to one.

  4. Identifying Optimal Temporal Scale for the Correlation of AOD and Ground Measurements of PM2.5 to Improve the Model Performance in a Real-time Air Quality Estimation System

    NASA Technical Reports Server (NTRS)

    Li, Hui; Faruque, Fazlay; Williams, Worth; Al-Hamdan, Mohammad; Luvall, Jeffrey C.; Crosson, William; Rickman, Douglas; Limaye, Ashutosh

    2009-01-01

    Aerosol optical depth (AOD), an indirect estimate of particle matter using satellite observations, has shown great promise in improving estimates of PM 2.5 air quality surface. Currently, few studies have been conducted to explore the optimal way to apply AOD data to improve the model accuracy of PM 2.5 surface estimation in a real-time air quality system. We believe that two major aspects may be worthy of consideration in that area: 1) the approach to integrate satellite measurements with ground measurements in the pollution estimation, and 2) identification of an optimal temporal scale to calculate the correlation of AOD and ground measurements. This paper is focused on the second aspect on the identifying the optimal temporal scale to correlate AOD with PM2.5. Five following different temporal scales were chosen to evaluate their impact on the model performance: 1) within the last 3 days, 2) within the last 10 days, 3) within the last 30 days, 4) within the last 90 days, and 5) the time period with the highest correlation in a year. The model performance is evaluated for its accuracy, bias, and errors based on the following selected statistics: the Mean Bias, the Normalized Mean Bias, the Root Mean Square Error, Normalized Mean Error, and the Index of Agreement. This research shows that the model with the temporal scale of within the last 30 days displays the best model performance in this study area using 2004 and 2005 data sets.

  5. Professional Rugby Union players have a 60% greater risk of time loss injury after concussion: a 2-season prospective study of clinical outcomes

    PubMed Central

    Cross, Matthew; Kemp, Simon; Smith, Andrew; Trewartha, Grant; Stokes, Keith

    2016-01-01

    Aim To investigate incidence of concussion, clinical outcomes and subsequent injury risk following concussion. Methods In a two-season (2012/2013, 2013/2014) prospective cohort study, incidence of diagnosed match concussions (injuries/1000 h), median time interval to subsequent injury of any type (survival time) and time spent at each stage of the graduated return to play pathway were determined in 810 professional Rugby Union players (1176 player seasons). Results Match concussion incidence was 8.9/1000 h with over 50% occurring in the tackle. Subsequent incidence of any injury for players who returned to play in the same season following a diagnosed concussion (122/1000 h, 95% CI 106 to 141) was 60% higher (IRR 1.6, 95% CI 1.4 to 1.8) than for those who did not sustain a concussion (76/1000 h, 95% CI 72 to 80). Median time to next injury following return to play was shorter following concussion (53 days, 95% CI 41 to 64) than following non-concussive injuries (114 days, 95% CI 85 to 143). 38% of players reported recurrence of symptoms or failed to match their baseline neurocognitive test during the graduated return to play protocol. Summary and conclusions Players who returned to play in the same season after a diagnosed concussion had a 60% greater risk of time-loss injury than players without concussion. A substantial proportion of players reported recurrence of symptoms or failed to match baseline neurocognitive test scores during graduated return to play. These data pave the way for trials of more conservative and comprehensive graduated return to play protocols, with a greater focus on active rehabilitation. PMID:26626266

  6. Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012

    NASA Astrophysics Data System (ADS)

    Visser, S.; Slowik, J. G.; Furger, M.; Zotter, P.; Bukowiecki, N.; Dressler, R.; Flechsig, U.; Appel, K.; Green, D. C.; Tremper, A. H.; Young, D. E.; Williams, P. I.; Allan, J. D.; Herndon, S. C.; Williams, L. R.; Mohr, C.; Xu, L.; Ng, N. L.; Detournay, A.; Barlow, J. F.; Halios, C. H.; Fleming, Z. L.; Baltensperger, U.; Prévôt, A. S. H.

    2014-06-01

    Ambient concentrations of trace elements with 2 h time resolution were measured in PM10-2.5, PM2.5-1.0 and PM1.0-0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 11.6 to 18.5 for SW winds (3.6-9.4 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.6 to 8.0 for SW (2.6-6.5 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10-2.5 mass fraction, roughly 3 times that of the PM1.0-0.3 fraction. These elements also showed the highest urban increments (∼3.0), although no difference was observed between brake wear and other traffic-related elements. Traffic-related elements exhibited higher concentrations during morning and evening rush hour, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (2.0-4.1 for SW, 1.4-2.1 for NE) and urban (1.7-2.3) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10-2.5 sea salt (factor of 1.5-2.0), which may be influenced by traffic

  7. Kerb and urban increment of highly time-resolved trace elements in PM10, PM2.5 and PM1.0 winter aerosol in London during ClearfLo 2012

    NASA Astrophysics Data System (ADS)

    Visser, S.; Slowik, J. G.; Furger, M.; Zotter, P.; Bukowiecki, N.; Dressler, R.; Flechsig, U.; Appel, K.; Green, D. C.; Tremper, A. H.; Young, D. E.; Williams, P. I.; Allan, J. D.; Herndon, S. C.; Williams, L. R.; Mohr, C.; Xu, L.; Ng, N. L.; Detournay, A.; Barlow, J. F.; Halios, C. H.; Fleming, Z. L.; Baltensperger, U.; Prévôt, A. S. H.

    2015-03-01

    Ambient concentrations of trace elements with 2 h time resolution were measured in PM10-2.5, PM2.5-1.0 and PM1.0-0.3 size ranges at kerbside, urban background and rural sites in London during winter 2012. Samples were collected using rotating drum impactors (RDIs) and subsequently analysed with synchrotron radiation-induced X-ray fluorescence spectrometry (SR-XRF). Quantification of kerb and urban increments (defined as kerb-to-urban and urban-to-rural concentration ratios, respectively), and assessment of diurnal and weekly variability provided insight into sources governing urban air quality and the effects of urban micro-environments on human exposure. Traffic-related elements yielded the highest kerb increments, with values in the range of 10.4 to 16.6 for SW winds (3.3-6.9 for NE) observed for elements influenced by brake wear (e.g. Cu, Sb, Ba) and 5.7 to 8.2 for SW (2.6-3.0 for NE) for other traffic-related processes (e.g. Cr, Fe, Zn). Kerb increments for these elements were highest in the PM10-2.5 mass fraction, roughly twice that of the PM1.0-0.3 fraction. These elements also showed the highest urban increments (~ 3.0), although no difference was observed between brake wear and other traffic-related elements. All elements influenced by traffic exhibited higher concentrations during morning and evening rush hours, and on weekdays compared to weekends, with the strongest trends observed at the kerbside site, and additionally enhanced by winds coming directly from the road, consistent with street canyon effects. Elements related to mineral dust (e.g. Al, Si, Ca, Sr) showed significant influences from traffic-induced resuspension, as evidenced by moderate kerb (3.4-5.4 for SW, 1.7-2.3 for NE) and urban (~ 2) increments and increased concentrations during peak traffic flow. Elements related to regional transport showed no significant enhancement at kerb or urban sites, with the exception of PM10-2.5 sea salt (factor of up to 2), which may be influenced by

  8. Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: Greater sage-grouse and cottontail rabbits

    USGS Publications Warehouse

    Fedy, B.C.; Doherty, K.E.

    2011-01-01

    Animal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse (Centrocercus urophasianus) and cottontail rabbits (Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles (r = 0. 77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes. ?? 2010 US Government.

  9. Population cycles are highly correlated over long time series and large spatial scales in two unrelated species: greater sage-grouse and cottontail rabbits.

    PubMed

    Fedy, Bradley C; Doherty, Kevin E

    2011-04-01

    Animal species across multiple taxa demonstrate multi-annual population cycles, which have long been of interest to ecologists. Correlated population cycles between species that do not share a predator-prey relationship are particularly intriguing and challenging to explain. We investigated annual population trends of greater sage-grouse (Centrocercus urophasianus) and cottontail rabbits (Sylvilagus sp.) across Wyoming to explore the possibility of correlations between unrelated species, over multiple cycles, very large spatial areas, and relatively southern latitudes in terms of cycling species. We analyzed sage-grouse lek counts and annual hunter harvest indices from 1982 to 2007. We show that greater sage-grouse, currently listed as warranted but precluded under the US Endangered Species Act, and cottontails have highly correlated cycles (r = 0.77). We explore possible mechanistic hypotheses to explain the synchronous population cycles. Our research highlights the importance of control populations in both adaptive management and impact studies. Furthermore, we demonstrate the functional value of these indices (lek counts and hunter harvest) for tracking broad-scale fluctuations in the species. This level of highly correlated long-term cycling has not previously been documented between two non-related species, over a long time-series, very large spatial scale, and within more southern latitudes.

  10. Synthesis of 2,5-bis(spirocyclohexane)-substituted nitroxides of pyrroline and pyrrolidine series, including thiol-specific spin label: an analogue of MTSSL with long relaxation time.

    PubMed

    Kirilyuk, Igor A; Polienko, Yuliya F; Krumkacheva, Olesya A; Strizhakov, Rodion K; Gatilov, Yurii V; Grigor'ev, Igor A; Bagryanskaya, Elena G

    2012-09-21

    The nitroxides of 7-azadispiro[5.1.5.2]pentadecane and 7-azadispiro[5.1.5.2]pentadeca-14-ene series have been prepared, including thiol-specific methane thiosulfonate spin label for site-directed spin labeling. The effect of spirocyclohexane moieties on chemical and spectral properties has been studied. The obtained temperature dependencies of electron spin relaxation parameters demonstrate that new nitroxides may be suitable for PELDOR distance measurements at 80-120 K. Moreover, the new nitroxides demonstrated much higher stability toward reduction by ascorbate than spirocyclohexane-substituted nitroxides of piperidine series and showed 1.3-3.14 times lower reduction rates compared to corresponding 2,2,5,5-tetramethyl nitroxides. PMID:22917445

  11. Effects of oil pollution at Kuwait's Greater Al-Burgan oil field on the timing of morning emergence, basking and foraging behaviors by the sand lizard Acanthodactylus scutellatus.

    PubMed

    Al-Hashem, M Abdulla; Brain, P F; Omar, S Ahmad

    2008-02-15

    An attempt was made to study the effects of oil pollution in a desert location (the Greater Al-Burgan oil fields, an area damaged in the second Gulf War) in Kuwait on the behaviour of the Sand lizard A. scutellatus. Polluted sites with apparently different degrees of contamination (namely tar mat, soot and clear sites) were compared with control areas outside this region. Between 2002 and 2003, ten lizards (5 of each sex) on each polluted and each control site were observed in the field at a time of the year when they were highly active. Air, substrate and burrow temperatures were recorded and lizards were monitored for their morning emergence times, as well as their basking and foraging activities. The present study confirmed that the morning emergence times and the basking behavior varied in sand lizards among the different pollution site categories. Physical changes in the tar mat sites caused the substrate temperatures in these locations to rise more quickly in the morning in response to solar gain than was the case in the other sites. This gives lizards in these locations the opportunity to emerge earlier and to start eating more quickly, giving them an energetic advantage (perhaps, in turn, influencing their rates of growth and fecundity). The clear sites had the next earliest emergence and were the next hottest but it is difficult to account for this in terms of the physical characteristics of this site. The basking times were clearly shorter on the dark soot and tar mat sites that appeared to have higher solar gain than control or clear sites. There did not appear to be any obvious differences in foraging activity of lizards in the different locations. It appears that some aspects of simple behaviour in these lizards provides a reliable, noninvasive indices for assessing oil pollution in desert locations. The precise impact of these changes in these reptiles on their long-term viability needs to be evaluated.

  12. A new method for the rapid analysis of 1H-Pyrrole-2,5-diones (maleimides) in environmental samples by two-dimensional gas chromatography time-of-flight mass spectrometry.

    PubMed

    Naeher, Sebastian; Lengger, Sabine K; Grice, Kliti

    2016-02-26

    Maleimides (1H-Pyrrole-2,5-diones) are monopyrrolic pigment derivatives with specific alkyl side chains that can be directly linked to their tetrapyrrole precursors, most notably chlorophylls and bacteriochlorophylls. These compounds can be used as palaeoenvironmental indicators such as algal productivity and redox conditions in ancient and modern aquatic systems. Here, we present a new method using two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-ToF-MS), which enables the rapid analysis of maleimides in complex mixtures and different matrices (e.g. sediments and soils), therefore largely simplifying the previous intricate maleimide purification protocol. This method also reduces the potential for bias associated with partial losses due to low recovery and the high volatility of maleimides. The maleimide distributions and concentrations obtained by GC × GC-ToF-MS were reproducible and in agreement with the previously used purification procedure followed by analysis with traditional gas chromatography-mass spectrometry (GC-MS). The new method also resolved previously unrecognised, partial coelution of some maleimides with unknown compounds by quantification with the m/z 75 fragment ion. Furthermore, the higher sensitivity enabled the detection of previously unrecognised and preliminarily identified maleimides based on their relative retention times. The new, easier, rapid and more sensitive GC×GC-ToF-MS method greatly facilitates the analysis of maleimides in environmental samples to study tetrapyrrole degradation processes and will further the development of maleimides as biomarkers for palaeoenvironmental reconstructions. PMID:26850318

  13. A new method for the rapid analysis of 1H-Pyrrole-2,5-diones (maleimides) in environmental samples by two-dimensional gas chromatography time-of-flight mass spectrometry.

    PubMed

    Naeher, Sebastian; Lengger, Sabine K; Grice, Kliti

    2016-02-26

    Maleimides (1H-Pyrrole-2,5-diones) are monopyrrolic pigment derivatives with specific alkyl side chains that can be directly linked to their tetrapyrrole precursors, most notably chlorophylls and bacteriochlorophylls. These compounds can be used as palaeoenvironmental indicators such as algal productivity and redox conditions in ancient and modern aquatic systems. Here, we present a new method using two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-ToF-MS), which enables the rapid analysis of maleimides in complex mixtures and different matrices (e.g. sediments and soils), therefore largely simplifying the previous intricate maleimide purification protocol. This method also reduces the potential for bias associated with partial losses due to low recovery and the high volatility of maleimides. The maleimide distributions and concentrations obtained by GC × GC-ToF-MS were reproducible and in agreement with the previously used purification procedure followed by analysis with traditional gas chromatography-mass spectrometry (GC-MS). The new method also resolved previously unrecognised, partial coelution of some maleimides with unknown compounds by quantification with the m/z 75 fragment ion. Furthermore, the higher sensitivity enabled the detection of previously unrecognised and preliminarily identified maleimides based on their relative retention times. The new, easier, rapid and more sensitive GC×GC-ToF-MS method greatly facilitates the analysis of maleimides in environmental samples to study tetrapyrrole degradation processes and will further the development of maleimides as biomarkers for palaeoenvironmental reconstructions.

  14. OBSERVABLE INDICATORS OF THE SENSITIVITY OF PM2.5 NITRATE TO EMISSION REDUCTIONS PART I: DERIVATION OF THE ADJUSTED GAS RATIO AND APPLICABILITY AT REGULATORY-RELEVANT TIME SCALES

    EPA Science Inventory

    Chemical transport models have frequently been used to evaluate the impacts of emission reductions on inorganic PM2.5. However, such models are limited in their accuracy by uncertain estimates of the spatial and temporal characterization of emissions and meteorology. Site-speci...

  15. The Internet Time Lag: Anticipating the Long-Term Consequences of the Information Revolution. A Report of the Annual Aspen Institute Roundtable on Information Technology (10th, Aspen, Colorado, August 2-5, 2001).

    ERIC Educational Resources Information Center

    Schwartz, Evan I.

    This is a report of the 10th annual Aspen Institute Roundtable on Information Technology (Aspen, Colorado, August 2-5, 2001). Participants were also polled after the events of September 11, and these comments have been integrated into the report. The mission of this report is to take a wide-ranging look at the trends that are defining the next new…

  16. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  17. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  18. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  19. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Bank compensation. 2.5 Section 2.5 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank compensation. (a) Nothing contained in this part prohibits a bank employee, officer, director, or...

  20. 28 CFR 2.5 - Sentence aggregation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Sentence aggregation. 2.5 Section 2.5 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS, YOUTH OFFENDERS, AND JUVENILE DELINQUENTS United States Code Prisoners and Parolees § 2.5...

  1. Intraurban concentrations, spatial variability and correlation of ambient polycyclic aromatic hydrocarbons (PAH) and PM2.5

    NASA Astrophysics Data System (ADS)

    Anastasopoulos, Angelos T.; Wheeler, Amanda J.; Karman, Deniz; Kulka, Ryan H.

    2012-11-01

    To investigate the intraurban spatial variability of air toxics associated with respirable particulate matter (PM), ambient PM2.5 and 16 polycyclic aromatic hydrocarbons (PAH) species (vapour phase plus 2.5 μm particle phase) were sampled over a dense network of sites in Hamilton, Ontario, Canada in June/July 2009 and December 2009. PM2.5 levels ranged from 2.46 to 11.0 μg m-3 in the summer campaign and 6.52 to 13.4 μg m-3 in the winter campaign. Total sampled PAH (Σ16PAH) levels ranged from 10.2 to 83.7 ng m-3 in the summer campaign and 8.31 to 52.1 ng m-3 in the winter campaign. Ambient PM2.5 and PAH concentrations were greater below the city's escarpment with a below/above escarpment difference in concentration much greater for PAH than for PM2.5 in both summer and winter sampling campaigns. Elevated levels of both pollutants were observed to occur near or downwind of the central business district and industrialized harbourfront area, suggesting the contribution of local sources. Ambient PAH exhibited a substantially greater degree of intraurban variability than PM2.5 (coefficient of variation approximately three times greater in summer campaign, four times greater in winter campaign) both above and below the escarpment, particularly for heavy MW species found predominantly in the particle phase. Benzo(a)Pyrene-equivalent toxicity (BaP-TEQ) associated with ambient PAH showed a generally similar spatial distribution to Σ16PAH; however, several sites with relatively low Σ16PAH had high BaP-TEQ (enriched in more toxic heavy MW species), indicating potential hotspots for elevated PAH exposures and local source contributions. Co-located field sampling data showed that central site monitoring was a poor proxy for PM2.5 and particularly for PAH and associated toxicity (BaP-TEQ) across the urban centre, underestimating levels at many sites, likely due to the significant number of locally distributed sources and mixed land use. The much greater intraurban

  2. 28 CFR 2.5 - Sentence aggregation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Sentence aggregation. 2.5 Section 2.5 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS... by the Commission pursuant to these rules, and the prisoner has a single parole eligibility date...

  3. 28 CFR 2.5 - Sentence aggregation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Sentence aggregation. 2.5 Section 2.5 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS... by the Commission pursuant to these rules, and the prisoner has a single parole eligibility date...

  4. 28 CFR 2.5 - Sentence aggregation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Sentence aggregation. 2.5 Section 2.5 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS... by the Commission pursuant to these rules, and the prisoner has a single parole eligibility date...

  5. 28 CFR 2.5 - Sentence aggregation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Sentence aggregation. 2.5 Section 2.5 Judicial Administration DEPARTMENT OF JUSTICE PAROLE, RELEASE, SUPERVISION AND RECOMMITMENT OF PRISONERS... by the Commission pursuant to these rules, and the prisoner has a single parole eligibility date...

  6. Hemolymphangioma of Greater Omentum

    PubMed Central

    Pandey, Sagar; Fan, Miao; Chang, Dandan; Zhu, Junfeng; Zhu, Ying; Li, Ziping

    2016-01-01

    Abstract Hemolymphangioma is a rare vascular developmental error. It comprises malformed venous and lymphatic component in various proportion. To the best of our knowledge, only a few cases have been reported in the literature so far. Here, we report a case of huge intraperitoneal cystic mass in a 3-year-old boy that was presented to hospital with intractable abdominal pain. On examination, he had fever along with associated symptoms like cough and sputum. Abdomen was distended with no tenderness or rebound tenderness. On computed tomography scan, huge cystic mass was seen and was diagnosed as intraperitoneal benign cystic lesion. Excisional surgery of the lesion was planned. On surgery, lesion was found to be originated from greater omentum and no adhesion was seen in surrounding tissue. Complete excision of the lesion was done. Histopathological specimen after surgery suggested it to be hemolymphangioma. Follow-up for 6 months showed no recurrence. Hemolymphangioma of the greater omentum is benign tumor and accurate diagnosis before surgery is still a challenge. Presentation of disease may vary from simple well-defined cystic lesion to aggressive ill-defined lesion mimicking malignancy. Therefore, further research is needed to help doctor with preoperative radiological diagnosis and avoid unnecessary radical surgery. PMID:27124058

  7. Changes in time-use and drug use by young adults in poor neighbourhoods of Greater Buenos Aires, Argentina, after the political transitions of 2001-2002: Results of a survey

    PubMed Central

    2011-01-01

    Background In some countries, "Big Events" like crises and transitions have been followed by large increases in drug use, drug injection and HIV/AIDS. Argentina experienced an economic crisis and political transition in 2001/2002 that affected how people use their time. This paper studies how time use changes between years 2001 and 2004, subsequent to these events, were associated with drug consumption in poor neighbourhoods of Greater Buenos Aires. Methods In 2003-2004, 68 current injecting drug users (IDUs) and 235 young non-IDUs, aged 21-35, who lived in impoverished drug-impacted neighbourhoods in Greater Buenos Aires, were asked about time use then and in 2001. Data on weekly hours spent working or looking for work, doing housework/childcare, consuming drugs, being with friends, and hanging out in the neighbourhood, were studied in relation to time spent using drugs. Field observations and focus groups were also conducted. Results After 2001, among both IDUs and non-IDUs, mean weekly time spent working declined significantly (especially among IDUs); time spent looking for work increased, and time spent with friends and hanging out in the neighbourhood decreased. We found no increase in injecting or non-injecting drug consumption after 2001. Subjects most affected by the way the crises led to decreased work time and/or to increased time looking for work--and by the associated increase in time spent in one's neighbourhood--were most likely to increase their time using drugs. Conclusions Time use methods are useful to study changes in drug use and their relationships to every day life activities. In these previously-drug-impacted neighbourhoods, the Argentinean crisis did not lead to an increase in drug use, which somewhat contradicts our initial expectations. Nevertheless, those for whom the crises led to decreased work time, increased time looking for work, and increased time spent in indoor or outdoor neighbourhood environments, were likely to spend more time

  8. 43 CFR 3101.2-5 - Computation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) OIL AND GAS LEASING Issuance of Leases § 3101.2-5... more than 10 percent of the stock of a corporation which holds Federal oil and gas leases shall be the... holding of acreage in common by the same persons in excess of the maximum acreage specified in the...

  9. 36 CFR 2.5 - Research specimens.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Section 2.5 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR RESOURCE... outside of the park area and the primary purpose of the collection is to enhance the protection or... has the potential for improving the management and protection of park resources. (e) In park...

  10. 12 CFR 2.5 - Bank compensation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY SALES OF CREDIT LIFE INSURANCE § 2.5 Bank... turn over to the bank as compensation all income received from the sale of the credit life insurance to the bank's loan customers. (b) Income derived from credit life insurance sales to loan customers...

  11. Palladium-catalyzed 2,5-diheteroarylation of 2,5-dibromothiophene derivatives

    PubMed Central

    Belkessam, Fatma; Mohand, Aidene; Soulé, Jean-François

    2014-01-01

    Summary Conditions allowing the one pot 2,5-diheteroarylation of 2,5-dibromothiophene derivatives in the presence of palladium catalysts are reported. Using KOAc as the base, DMA as the solvent and only 0.5–2 mol % palladium catalysts, the target 2,5-diheteroarylated thiophenes were obtained in moderate to good yields and with a wide variety of heteroarenes such as thiazoles, thiophenes, furans, pyrroles, pyrazoles or isoxazoles. Moreover, sequential heteroarylation reactions allow the access to 2,5-diheteroarylated thiophenes bearing two different heteroaryl units. PMID:25550758

  12. Weekly cycle of magnetic characteristics of PM2.5 and PM2.5-10 in Beijing, China

    NASA Astrophysics Data System (ADS)

    SHI, M.; Wu, H.; Zhang, S.; Li, H.; Yang, T.

    2013-12-01

    In urban areas,fine particle matter with aerodynamic diameter between 2.5 um and 10 um (PM2.5-10), and 2.5 um (PM2.5), as an important source of urban particulate matter (PM) pollutants, have significant negative effects on health, atmospheric visibility and climate. PM has increasingly become a significant index of indicating the atmospheric pollution of city. In recent years, Beijing, China has been listed as one of the most serious air pollution city in the world. In order to investigate the sources of air pollutants, a total of 283 pairs of PM2.5 and PM2.5-10 samples were collected daily from July, 2010 to June, 2011 in Beijing. Mineral magnetic properties and Scanning electron microscope (SEM) observations and energy dispersive X-ray spectroscopy (EDS) analyses of PM2.5 and PM2.5-10 were measured to verify the magnetic materials. Magnetic measures for PM indicated that the major magnetic phase was coarse-grained magnetite-like material. The χlf, χarm, SIRM and χarm/SIRM series of the PM2.5 and PM2.5-10 show seasonal dependences: high values in winter and low values in summer. In additional the parameters analyzed by Time-series methods show a strong cycle about 7 days above 95% confidence level. Weekly cycle of magnetic characteristics of PM2.5 and PM2.5-10 show different pattern: the concentration of magnetic particles in PM2.5-10 show high values in mid-week, and particle sizes is steady, while the concentration of magnetic particles in PM2.5 show reverse a weekly cycle pattern, and particle sizes is smaller in the mid-week.Microscopy analyses reveal basically three morphologies of magnetic grains: aggregate, spherules and angular particles. The ultrafine carbonaceous particles which tend to form complex clusters and chain-like structures, most likely come from coal burning and motor vehicle exhaust. Spherical particles in PM2.5 are dominantly composed of Fe, O and C, grain-diameters of particles range from 0.3 to 2 um. Angular particles of Fe

  13. PATRAN 2.5/EAL interface guide

    NASA Technical Reports Server (NTRS)

    Feldhaus, Winifred S.

    1994-01-01

    The PATRAN/EA interface guide describes two programs, EALPAT and PATEAL. EALPAT reads an EAL LO1 file and translates the model and results into a PATRAN 2.5 neutral file, element results file, and nodal results file. An EAL model can be color coded in PATRAN, and geometry, loads, boundary conditions, section and material properties, rigid masses, springs, and beam orientations can be plotted and debugged. EAL results can be brought into PATRAN as element or nodal quantities and displayed as deformed plots, animated shapes, color coded elements, or color filled contour plots. PATEAL converts a PATRAN 2.5 data base into an EAL runstream. Geometry, including all element types, alternate coordinate systems, material properties, section properties, loads and boundary conditions are all converted. EALPAT and PATEAL can also be used together with the PATNAS translator from PDA Engineering to convert an EAL runstream to an MSC/NASTRAN bulk data file.

  14. MCNPX version 2.5.c

    SciTech Connect

    Hendricks, J. S.

    2003-01-01

    MCNPX is a Fortran 90 Monte Carlo radiation transport computer code that transports all particles at all energies. It is a superset of MCNP4C3, and has many capabilities beyond MCNP4C3. These capabilities are summarized along with their quality guarantee and code availability. Then the user interface changes from MCNP are described. Finally, the n.ew capabilities of the latest version, MCNPX 2.5.c, are documented. Future plans and references are also provided.

  15. Monitoing PM2.5 from Space

    NASA Astrophysics Data System (ADS)

    Chu, D.; Remer, L.; Szykman, J.; Kaumfan, Y.; Neil, D.; Pierce, B.

    2003-12-01

    MODIS sensors onboard the EOS Terra and Aqua satellites launched in 1999 and 2002 provide the revolutionized perspectives to study the Earth systems. MODIS ability to derive the first aerosol product over land has advanced our understanding of aerosols into the source regions. The analysis of MODIS-derived columnar aerosol loading has shown good correlation (correlation coefficient ~0.8-0.9) with EPA PM2.5 (particulate matter with particle size less than 2.5 mm) at surface in metropolitan areas (e.g., New York City, Chicago, Houston, etc.) and also over broad regions including 11 states and Washington DC. At present, the EPA, along with Regional Planning Organizations, and state and local governments use a multitude of decision support tools to assess, control, and report the nature of air pollution related to PM. However, the current existing air quality decision processes solely rely on urban scale model and ground-based network. Using MODIS aerosol data can aid significantly in tracking the movement of pollutants, which can be used as a proxy of PM2.5 for regions without ground measurements. NASA (GSFC and LaRC) is collaborating with EPA and NOAA in providing MODIS aerosol data to benchmark PM2.5 forecast in the East US in the summer 2003. This activity is to prototype similar activities in the following years using MODIS direct broadcasting to study transport (national, international, or intercontinental) issues and assess performance effectiveness of existing air quality regulations. Improvements of MODIS aerosol algorithm are planned to achieve better spatial resolution for urban pollution and health-related studies.

  16. Fructose hydrogenation to 2,5-dimethyltetrahydrofuran over a sulfur-poisoned Pt/C catalyst

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The conversion of biomass to a suite of chemicals will allow for greater financial stability for a biorefinery and greater use of field residues from farms resulting in increased farm income. To that end, we have hydrogenated fructose to 2,5-dimethyltetrahydrofuran in 50% yield using 5%Pt/Carbon poi...

  17. 2,5-diketopiperazines as neuroprotective agents.

    PubMed

    Cornacchia, C; Cacciatore, I; Baldassarre, L; Mollica, A; Feliciani, F; Pinnen, F

    2012-01-01

    2,5-diketopiperazines are the simplest cyclic peptides found in nature, commonly biosynthesized from amino acids by different organisms, and represent a promising class of biologically active natural products. Their peculiar heterocyclic structure confers high stability against the proteolysis and constitutes a structural requirement for the active intestinal absorption. Furthermore, the diketopiperazine-based motif is considered as a novel brain shuttle for the delivery of drugs with limited ability to cross the blood-brain barrier (BBB) and can be proposed as an ideal candidate for the rational development of new therapeutic agents. Although these cyclic peptides have been known since the beginning of the 20th century, only recently have they attracted substantial interest with respect to the wide spectrum of their biological properties, including antitumor, antiviral, antifungal, antibacterial and antihyperglycemic activities. In addition to these, the most challenging function of the diketopiperazine derivatives is related with their remarkable neuroprotective and nootropic activity. The aim of the present paper is to provide an overview of the two major classes of diketopiperazines, the TRH-related and the unsaturated derivatives both characterized by a significant ability to protect against neurotoxicity in several experimental models. The neuroprotective profile of these compounds suggests that they may have a future utility in the therapy of neuronal degeneration in vivo, potentially through several different mechanisms.

  18. Source apportionment of PM2.5 in Incheon, Korea

    NASA Astrophysics Data System (ADS)

    Choi, J.; Ban, S.; Lee, C.; Yi, S.; Zoh, K.

    2011-12-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Incheon, Korea, every third day from Jun 2009 to may 2010 and analyzed their chemical species. In this study, we investigated the source of PM2.5 using Positive Matrix Factorization(PMF), the source area from Potential Source Contribution Function (PSCF) and Conditional Probability Function(CPF), and characterized source variation among episode, non-episode, yellow sand events. Incheon, study site, is located at the mid-western tip of the Korean Peninsula with a population of 2.6 million people and area of 1029.4 km2, respectively. As a transportation hub, the city also holds the importance of meteological/geological aspect affecting the air quality of capital region, in that is prevailing westerlies zone and a air passageway from China to Japan passing through seoul, korea. In the study, the Four channel based on Annular Denuder System(ADS) were used for sample collection(URG co, USA). The filter samples were analyzed with respect to species type such as ion group, metal, and OC/EC compound using ion chromatography, ICP/MS, and NIOSH TOT method, respectively. The PM2.5 concentration was 43ug/m3 that is almost three times higher than the US NAAQS annual PM2.5 standard of 15ug/m3. Nine PM2.5 sources were resolved from PMF analysis that provided reasonable source profiles and interesting insights into the source contributions to the ambient mass concentrations. The major sources of PM2.5 were secondary nitrate(26.4%), secondary sulfate(17.3%), gasoline(16.4%), and residual oil combustion(13.5%), with lesser contributions from biomass burning (7.5%), road dust(6.9%), soil (5.5%), coal fire powerplant (4.0%), and free sea salt(2.4%). CPF results identified possible local source directions such as motor vehicles, free sea salt. PSCF results indicated that likely pollution areas increased secondary particle concentrations(sulfate and nitrate) in Incheon to be the major industrial areas in China

  19. Seasonal variability of PM2.5 composition and sources in the Klang Valley urban-industrial environment

    NASA Astrophysics Data System (ADS)

    Amil, Norhaniza; Talib Latif, Mohd; Firoz Khan, Md; Mohamad, Maznorizan

    2016-04-01

    This study investigates the fine particulate matter (PM2.5) variability in the Klang Valley urban-industrial environment. In total, 94 daily PM2.5 samples were collected during a 1-year campaign from August 2011 to July 2012. This is the first paper on PM2.5 mass, chemical composition and sources in the tropical environment of Southeast Asia, covering all four seasons (distinguished by the wind flow patterns) including haze events. The samples were analysed for various inorganic components and black carbon (BC). The chemical compositions were statistically analysed and the temporal aerosol pattern (seasonal) was characterised using descriptive analysis, correlation matrices, enrichment factor (EF), stoichiometric analysis and chemical mass closure (CMC). For source apportionment purposes, a combination of positive matrix factorisation (PMF) and multi-linear regression (MLR) was employed. Further, meteorological-gaseous parameters were incorporated into each analysis for improved assessment. In addition, secondary data of total suspended particulate (TSP) and coarse particulate matter (PM10) sampled at the same location and time with this study (collected by Malaysian Meteorological Department) were used for PM ratio assessment. The results showed that PM2.5 mass averaged at 28 ± 18 µg m-3, 2.8-fold higher than the World Health Organisation (WHO) annual guideline. On a daily basis, the PM2.5 mass ranged between 6 and 118 µg m-3 with the daily WHO guideline exceeded 43 % of the time. The north-east (NE) monsoon was the only season with less than 50 % sample exceedance of the daily WHO guideline. On an annual scale, PM2.5 mass correlated positively with temperature (T) and wind speed (WS) but negatively with relative humidity (RH). With the exception of NOx, the gases analysed (CO, NO2, NO and SO2) were found to significantly influence the PM2.5 mass. Seasonal variability unexpectedly showed that rainfall, WS and wind direction (WD) did not significantly correlate

  20. Retrospective prediction of intraurban spatiotemporal distribution of PM2.5 in Taipei

    NASA Astrophysics Data System (ADS)

    Hwa-Lung, Yu; Chih-Hsin, Wang

    2010-08-01

    Numerous studies have shown that fine airborne particulate matter particles (PM2.5) are more dangerous to human health than coarse particles, e.g. PM10. The assessment of the impacts to human health or ecological effects by long-term PM2.5 exposure is often limited by lack of PM2.5 measurements. In Taipei, PM2.5 was not systematically observed until August, 2005. Taipei is the largest metropolitan area in Taiwan, where a variety of industrial and traffic emissions are continuously generated and distributed across space and time. PM-related data, i.e., PM10 and Total Suspended Particles (TSP) are independently systematically collected by different central and local government institutes. In this study, the retrospective prediction of spatiotemporal distribution of monthly PM2.5 over Taipei will be performed by using Bayesian Maximum Entropy method (BME) to integrate (a) the spatiotemporal dependence among PM measurements (i.e. PM10, TSP, and PM2.5), (b) the site-specific information of PM measurements which can be certain or uncertain information, and (c) empirical evidence about the PM2.5/PM10 and PM10/TSP ratios. The performance assessment of the retrospective prediction for the spatiotemporal distribution of PM2.5 was performed over space and time during 2003-2004 by comparing the posterior pdf of PM2.5 with the observations. Results show that the incorporation of PM10 and TSP observations by BME method can effectively improve the spatiotemporal PM2.5 estimation in the sense of lower mean and standard deviation of estimation errors. Moreover, the spatiotemporal retrospective prediction with PM2.5/PM10 and PM2.5/TSP ratios can provide good estimations of the range of PM2.5 levels over space and time during 2003-2004 in Taipei.

  1. Paleotectonic and paleogeographic evolution of greater China

    SciTech Connect

    Yilmaz, P.O.; Norton, I.O. )

    1996-01-01

    In this study, we utilize plate tectonic history of Central Asia to constrain understanding of sedimentary basin development and to show how regional scale tectonic events affect play elements for major basins of greater China. Tectonic framework and paleogeography are used as a constraint on models for basin formation, climate distribution and accommodation which in turn control distribution of reservoir, source, seal and trap. Greater China is an artifact of Phanerozoic tectonics. It has a protracted history of continental deformation as amalgamation of crustal blocks and island arc/subduction and accretion complexes occurred. Early Paleozoic hydrocarbon systems are dominated by extensive carbonate platform and Permian and younger systems are dominated by continental and lacustrine sedimentation. The basement of greater China consists of continental and accretion crust. The crustal blocks include South and North China, Indochina, Tibet and Tarim, and accretion blocks include the Altaids and Manchurides. The relative positions and interactions of these blocks during Paleozic and Mesozoic time resulted in formation of greater China. Final amalgamation and deformation occurred in Eocene time when India collided with Asia. The discussions consist of presentation of a model for tectonic evolution of these blocks and their paleogeography through Phanerozoic time. This is done with maps at 1:8 million scale covering nine time slices, three in the Paleozoic, three in the Mesozoic and three in the Cenozoic.

  2. Paleotectonic and paleogeographic evolution of greater China

    SciTech Connect

    Yilmaz, P.O.; Norton, I.O.

    1996-12-31

    In this study, we utilize plate tectonic history of Central Asia to constrain understanding of sedimentary basin development and to show how regional scale tectonic events affect play elements for major basins of greater China. Tectonic framework and paleogeography are used as a constraint on models for basin formation, climate distribution and accommodation which in turn control distribution of reservoir, source, seal and trap. Greater China is an artifact of Phanerozoic tectonics. It has a protracted history of continental deformation as amalgamation of crustal blocks and island arc/subduction and accretion complexes occurred. Early Paleozoic hydrocarbon systems are dominated by extensive carbonate platform and Permian and younger systems are dominated by continental and lacustrine sedimentation. The basement of greater China consists of continental and accretion crust. The crustal blocks include South and North China, Indochina, Tibet and Tarim, and accretion blocks include the Altaids and Manchurides. The relative positions and interactions of these blocks during Paleozic and Mesozoic time resulted in formation of greater China. Final amalgamation and deformation occurred in Eocene time when India collided with Asia. The discussions consist of presentation of a model for tectonic evolution of these blocks and their paleogeography through Phanerozoic time. This is done with maps at 1:8 million scale covering nine time slices, three in the Paleozoic, three in the Mesozoic and three in the Cenozoic.

  3. Bison in the greater Yellowstone

    USGS Publications Warehouse

    Meagher, Mary

    1994-01-01

    In the Greater Yellowstone Area, free-ranging bison occur in Jackson Hole, Wyoming, and Yellowstone National Park. The Yellowstone population is discussed, with emphasis on changes in numbers from approximately 400 in 1968 to about 3500 now. Major influences for change initially were natural; more recently the winter road system used by snowmobiles appeared to be the dominant factor. The situation is in a state of flux. Interagency planning is in progress to address management alternatives for conflicts outside the park.

  4. SU-E-J-09: Image Quality Comparison and Dose Quantification for 2.5 MV

    SciTech Connect

    Stowe, M; DiCostanzo, D; Ayan, A; Woollard, J; Gupta, N

    2015-06-15

    Purpose: To compare the image quality of the 2.5MV imaging beam (2.5X-IMB) to that of a 6MV beam and to quantify the imaging dose of a 2.5X-IMB for constancy as specified by AAPM TG-142 Methods: The image quality of the 2.5X-IMB was compared to the 6MV imaging beam using the SNC ImagePro MV-QA phantom and the Varian supplied Las Vegas phantom (LVP). High resolution (1280×1280×16, 2 frames at 1.5MU/frame) and low resolution (640×640×16, 2 frames at 0.75MU/frame) images were compared for each phantom. MV-QA phantom images were evaluated quantitatively, and the LVP images were evaluated qualitatively. The imaging dose for 2.5X-IMB was quantified using the procedure outlined in TG51. PTWCC13-31013 chambers were used to measure a percent depth dose (PDD) curve for the 2.5X-IMB. All the factors described in TG51 were calculated using the 2.5X-IMB and a PTW30013 farmer chamber. Results: A comparison between 2.5X-IMB and 6MV image quality was performed both visually and with DoseLab software. The optimal window and level were set for each image of the LVP by the user. Visual inspection showed greater contrast resolution with the 2.5MV beam, but no significant difference with the change in imaging resolution. DoseLab reported similar spatial resolutions between the two energies, but the contrast-to-noise ratio (CNR) was greater for 2.5MV. The PDDx(10cm) for a 10x10cm2 field was measured to be 51.5%. Although this PDD value is off the scale of Figure 4 in TG51, the trend of the curve corresponding to the PTW31003 (equivalent) chamber led to an approximate kQ value of 1.00. Conclusion: When compared to 6MV imaging, 2.5X-IMB results in a better CNR. At low resolution, the DoseLab results for the two energies are comparable, but visual analysis favors the 2.5X-IMB images. Imaging dose was quantified for the 2.5X-IMB after following the TG51 methodology with appropriate approximations.

  5. Potentiation of 2,5-hexanedione neurotoxicity by methyl ethyl ketone

    SciTech Connect

    Ralston, W.H.; Hilderbrand, R.L.; Uddin, D.E.; Andersen, M.E.; Gardier, R.W.

    1985-11-01

    Chronic oral administration of a combination of 2.2 mmol methyl ethyl ketone (MEK) and 2.2 mmol 2,5-hexanedione (2,5-HD)/kg/day, 5 days/week resulted in more rapid onset of motor deficits than did chronic dosing with 2.2 mmol 2,5-HD/kg/day alone. In kinetic studies blood time courses of 2,5-HD were determined in rats in the presence and absence of MEK. Concomitant administration of MEK reduced blood 2,5-HD clearance and increased the area under the curve (AUC) for the blood 2,5-HD. In companion experiments with 2,5-(1,6-/sup 14/C)HD as a tracer, neural and nonneural tissues were examined 72 hr following the last treatment at Weeks 1, 2, and 3 of chronic administration of 2,5-HD alone or in combination with an equimolar dose of MEK. Rats treated with 2,5-(/sup 14/C)HD alone or in combination with MEK demonstrated no difference in total or trichloroacetic acid-precipitable radioactivity in blood, in liver homogenates, or in neurofilament-enriched fractions from sciatic nerve and spinal cord. The data support a suggestion that the potentiation of hexacarbon neurotoxicity by MEK is the result of the persistence of the neurotoxic metabolite in the blood and not the enhanced metabolism of parent hexacarbon to 2,5-HD.

  6. Population Exposure to PM2.5 in the Urban Area of Beijing

    PubMed Central

    Zhang, An; Qi, Qingwen; Jiang, Lili; Zhou, Fang; Wang, Jinfeng

    2013-01-01

    The air quality in Beijing, especially its PM2.5 level, has become of increasing public concern because of its importance and sensitivity related to health risks. A set of monitored PM2.5 data from 31 stations, released for the first time by the Beijing Environmental Protection Bureau, covering 37 days during autumn 2012, was processed using spatial interpolation and overlay analysis. Following analyses of these data, a distribution map of cumulative exceedance days of PM2.5 and a temporal variation map of PM2.5 for Beijing have been drawn. Computational and analytical results show periodic and directional trends of PM2.5 spreading and congregating in space, which reveals the regulation of PM2.5 overexposure on a discontinuous medium-term scale. With regard to the cumulative effect of PM2.5 on the human body, the harm from lower intensity overexposure in the medium term, and higher overexposure in the short term, are both obvious. Therefore, data of population distribution were integrated into the aforementioned PM2.5 spatial spectrum map. A spatial statistical analysis revealed the patterns of PM2.5 gross exposure and exposure probability of residents in the Beijing urban area. The methods and conclusions of this research reveal relationships between long-term overexposure to PM2.5 and people living in high-exposure areas of Beijing, during the autumn of 2012. PMID:23658832

  7. Structural characterization of native high-methoxylated pectin using nuclear magnetic resonance spectroscopy and ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Comparative use of 2,5-dihydroxybenzoic acid and nor-harmane as UV-MALDI matrices.

    PubMed

    Monge, María Eugenia; Negri, R Martín; Kolender, Adriana A; Erra-Balsells, Rosa

    2007-01-01

    The successful analysis by ultraviolet matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (UV-MALDI-TOF MS) of native and hydrolyzed high-methoxylated pectin samples is described. In order to find the optimal conditions for UV-MALDI-TOF MS analysis several experimental variables were studied such as: different UV-MALDI matrices (nor-harmane, 2,5-dihydroxybenzoic acid), sample preparation methods (mixture, sandwich), inorganic salt addition (doping salts, NaCl, KCl, NH(4)Cl), ion mode (positive, negative), linear and reflectron mode, etc. nor-Harmane has never been used as a UV-MALDI matrix for the analysis of pectins but its use avoids pre-treatment of the sample, such as an enzymatic digestion or an acid hydrolysis, and there is no need to add salts, making the analysis easier and faster. This study suggested an alternative way of analyzing native high-methoxylated pectins, with UV-MALDI-TOF MS, by using nor-harmane as the matrix in negative ion mode. The analysis by (1)H and (13)C nuclear magnetic resonance (NMR) spectroscopy of the native and hydrolyzed pectin is also briefly described.

  8. 42 CFR 2.5 - Reports of violations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Reports of violations. 2.5 Section 2.5 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL PROVISIONS CONFIDENTIALITY OF ALCOHOL AND DRUG ABUSE PATIENT RECORDS Introduction § 2.5 Reports of violations. (a) The report...

  9. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the...

  10. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Preclosure Guidelines Environment, Socioeconomics, and Transportation § 960.5-2-5...

  11. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  12. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  13. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  14. 10 CFR 960.4-2-5 - Erosion.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Erosion. 960.4-2-5 Section 960.4-2-5 Energy DEPARTMENT OF... Postclosure Guidelines § 960.4-2-5 Erosion. (a) Qualifying condition. The site shall allow the underground... consider the climatic, tectonic, and geomorphic evidence of rates and patterns of erosion in the...

  15. 4 CFR 2.5 - Prohibited personnel practices.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 4 Accounts 1 2010-01-01 2010-01-01 false Prohibited personnel practices. 2.5 Section 2.5 Accounts GOVERNMENT ACCOUNTABILITY OFFICE PERSONNEL SYSTEM PURPOSE AND GENERAL PROVISION § 2.5 Prohibited personnel... concerning, the merit system principles described in § 2.4. (l) Information to the Congress. Nothing in...

  16. 2'-phosphodiesterase and 2',5'-oligoadenylate synthetase activities in the lowest metazoans, sponge [porifera].

    PubMed

    Saby, Emilie; Poulsen, Jesper Buchhave; Justesen, Just; Kelve, Merike; Uriz, Maria Jesus

    2009-01-01

    Sponges [porifera], the most ancient metazoans, contain modules related to the vertebrate immune system, including the 2',5'-oligoadenylate synthetase (OAS). The components of the antiviral 2',5'-oligoadenylate (2-5A) system (OAS, 2'-Phosphodiesterase (2'-PDE) and RNAse L) of vertebrates have not all been identified in sponges. Here, we demonstrate for the first time that in addition to the OAS activity, sponges possess a 2'-PDE activity, which highlights the probable existence of a premature 2-5A system. Indeed, Suberites domuncula and Crella elegans exhibited this 2-5A degrading activity. Upon this finding, two out of three elements forming the 2-5A system have been found in sponges, only a endoribonuclease, RNAse L or similar, has to be found. We suspect the existence of a complex immune system in sponges, besides the self/non-self recognition system and the use of phagocytosis and secondary metabolites against pathogens.

  17. CARDIOVASCULAR MORTALITY IN PHOENIX: PM1 IS A BETTER INDICATOR THAN PM2.5.

    EPA Science Inventory

    EPA has obtained a 3-year database of particulate matter (PM) in Phoenix, AZ from 1995 - 1997 that includes elemental analysis by XRF of daily PM2.5. During this time period PM1 and PM2.5 TEOMs were run simultaneously for about 7 months during two periods of the year. Regressio...

  18. Intra-urban spatial variability of PM2.5-bound carbonaceous components

    PubMed Central

    Xie, Mingjie; Coons, Teresa L.; Dutton, Steven J.; Milford, Jana B.; Miller, Shelly L.; Peel, Jennifer L.; Vedal, Sverre; Hannigan, Michael P.

    2014-01-01

    The Denver Aerosol Sources and Health (DASH) study was designed to evaluate associations between PM2.5 species and sources and adverse human health effects. The DASH study generated a five-year (2003–2007) time series of daily speciated PM2.5 concentration measurements from a single, special-purpose monitoring site in Denver, CO. To evaluate the ability of this site to adequately represent the short term temporal variability of PM2.5 concentrations in the five county Denver metropolitan area, a one year supplemental set of PM2.5 samples was collected every sixth day at the original DASH monitoring site and concurrently at three additional sites. Two of the four sites, including the original DASH site, were located in residential areas at least 1.9 km from interstate highways. The other two sites were located within 0.3 km of interstate highways. Concentrations of elemental carbon (EC), organic carbon (OC), and 58 organic molecular markers were measured at each site. To assess spatial variability, site pairs were compared using the Pearson correlation coefficient (r) and coefficient of divergence (COD), a statistic that provides information on the degree of uniformity between monitoring sites. Biweekly co-located samples collected from July 2004 to September 2005 were also analyzed and used to estimate the uncertainty associated with sampling and analytical measurement for each species. In general, the two near-highway sites exhibited higher concentrations of EC, OC, polycyclic aromatic hydrocarbons (PAHs), and steranes than did the more residential sites. Lower spatial heterogeneity based on r and COD was inferred for all carbonaceous species after considering their divergence and lack of perfect correlations in co-located samples. Ratio–ratio plots combined with available gasoline- and diesel-powered motor vehicle emissions profiles for the region suggested a greater impact to high molecular weight (HMW) PAHs from diesel-powered vehicles at the near

  19. Status and characteristics of ambient PM2.5 pollution in global megacities.

    PubMed

    Cheng, Zhen; Luo, Lina; Wang, Shuxiao; Wang, Yungang; Sharma, Sumit; Shimadera, Hikari; Wang, Xiaoliang; Bressi, Michael; de Miranda, Regina Maura; Jiang, Jingkun; Zhou, Wei; Fajardo, Oscar; Yan, Naiqiang; Hao, Jiming

    2016-01-01

    Ambient PM2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM2.5 pollution of 45 global megacities in 2013, based on mass concentration from official monitoring networks and composition data reported in the literature. The results showed that the five most polluted megacities were Delhi, Cairo, Xi'an, Tianjin and Chengdu, all of which had an annual average concentration of PM2.5 greater than 89μg/m(3). The five cleanest megacities were Miami, Toronto, New York, Madrid and Philadelphia, the annual averages of which were less than 10μg/m(3). Spatial distribution indicated that the highly polluted megacities are concentrated in east-central China and the Indo-Gangetic Plain. Organic matter and SNA (sum of sulfate, nitrate and ammonium) contributed 30% and 36%, respectively, of the average PM2.5 mass for all megacities. Notable seasonal variation of PM2.5 polluted days was observed, especially for the polluted megacities of China and India, resulting in frequent heavy pollution episodes occurring during more polluted seasons such as winter. Marked differences in PM2.5 pollution between developing and developed megacities require more effort on local emissions reduction as well as global cooperation to address the PM2.5 pollution of those megacities mainly in Asia.

  20. Status and characteristics of ambient PM2.5 pollution in global megacities.

    PubMed

    Cheng, Zhen; Luo, Lina; Wang, Shuxiao; Wang, Yungang; Sharma, Sumit; Shimadera, Hikari; Wang, Xiaoliang; Bressi, Michael; de Miranda, Regina Maura; Jiang, Jingkun; Zhou, Wei; Fajardo, Oscar; Yan, Naiqiang; Hao, Jiming

    2016-01-01

    Ambient PM2.5 pollution is a substantial threat to public health in global megacities. This paper reviews the PM2.5 pollution of 45 global megacities in 2013, based on mass concentration from official monitoring networks and composition data reported in the literature. The results showed that the five most polluted megacities were Delhi, Cairo, Xi'an, Tianjin and Chengdu, all of which had an annual average concentration of PM2.5 greater than 89μg/m(3). The five cleanest megacities were Miami, Toronto, New York, Madrid and Philadelphia, the annual averages of which were less than 10μg/m(3). Spatial distribution indicated that the highly polluted megacities are concentrated in east-central China and the Indo-Gangetic Plain. Organic matter and SNA (sum of sulfate, nitrate and ammonium) contributed 30% and 36%, respectively, of the average PM2.5 mass for all megacities. Notable seasonal variation of PM2.5 polluted days was observed, especially for the polluted megacities of China and India, resulting in frequent heavy pollution episodes occurring during more polluted seasons such as winter. Marked differences in PM2.5 pollution between developing and developed megacities require more effort on local emissions reduction as well as global cooperation to address the PM2.5 pollution of those megacities mainly in Asia. PMID:26891184

  1. [Autoerotic fatalities in Greater Dusseldorf].

    PubMed

    Hartung, Benno; Hellen, Florence; Borchard, Nora; Huckenbeck, Wolfgang

    2011-01-01

    Autoerotic fatalities in the Greater Dusseldorf area correspond to the relevant medicolegal literature. Our results included exclusively young to middle-aged, usually single men who were found dead in their city apartments. Clothing and devices used showed a great variety. Women's or fetish clothing and complex shackling or hanging devices were disproportionately frequent. In most cases, death occurred due to hanging or ligature strangulation. There was no increased incidence of underlying psychiatric disorders. In most of the deceased no or at least no remarkable alcohol intoxication was found. Occasionally, it may be difficult to reliably differentiate autoerotic accidents, accidents occurring in connection with practices of bondage & discipline, dominance & submission (BDSM) from natural death, suicide or homicide. PMID:22039693

  2. Planning for greater confinement disposal

    SciTech Connect

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1985-01-01

    A report that provides guidance for planning for greater-confinement disposal (GCD) of low-level radioactive waste is being prepared. The report addresses procedures for selecting a GCD technology and provides information for implementing these procedures. The focus is on GCD; planning aspects common to GCD and shallow-land burial are covered by reference. Planning procedure topics covered include regulatory requirements, waste characterization, benefit-cost-risk assessment and pathway analysis methodologies, determination of need, waste-acceptance criteria, performance objectives, and comparative assessment of attributes that support these objectives. The major technologies covered include augered shafts, deep trenches, engineered structures, hydrofracture, improved waste forms, and high-integrity containers. Descriptive information is provided, and attributes that are relevant for risk assessment and operational requirements are given. 10 refs., 3 figs., 2 tabs.

  3. Spatiotemporal Variability of Remotely Sensed PM2.5 Concentrations in China from 1998 to 2014 Based on a Bayesian Hierarchy Model.

    PubMed

    Li, Junming; Jin, Meijun; Xu, Zheng

    2016-01-01

    With the rapid industrial development and urbanization in China over the past three decades, PM2.5 pollution has become a severe environmental problem that threatens public health. Due to its unbalanced development and intrinsic topography features, the distribution of PM2.5 concentrations over China is spatially heterogeneous. In this study, we explore the spatiotemporal variations of PM2.5 pollution in China and four great urban areas from 1998 to 2014. A space-time Bayesian hierarchy model is employed to analyse PM2.5 pollution. The results show that a stable "3-Clusters" spatial PM2.5 pollution pattern has formed. The mean and 90% quantile of the PM2.5 concentrations in China have increased significantly, with annual increases of 0.279 μg/m³ (95% CI: 0.083-0.475) and 0.735 μg/m³ (95% CI: 0.261-1.210), respectively. The area with a PM2.5 pollution level of more than 70 μg/m³ has increased significantly, with an annual increase of 0.26 percentage points. Two regions in particular, the North China Plain and Sichuan Basin, are experiencing the largest amounts of PM2.5 pollution. The polluted areas, with a high local magnitude of more than 1.0 relative to the overall PM2.5 concentration, affect an area with a human population of 949 million, which corresponded to 69.3% of the total population in 2010. North and south differentiation occurs in the urban areas of the Jingjinji and Yangtze Delta, and circular and radial gradient differentiation occur in the urban areas of the Cheng-Yu and Pearl Deltas. The spatial heterogeneity of the urban Jingjinji group is the strongest. Eighteen cities located in the Yangtze Delta urban group, including Shanghai and Nanjing, have experienced high PM2.5 concentrations and faster local trends of increasing PM2.5. The percentage of exposure to PM2.5 concentrations greater than 70 μg/m³ and 100 μg/m³ is increasing significantly. PMID:27490557

  4. Spatiotemporal Variability of Remotely Sensed PM2.5 Concentrations in China from 1998 to 2014 Based on a Bayesian Hierarchy Model

    PubMed Central

    Li, Junming; Jin, Meijun; Xu, Zheng

    2016-01-01

    With the rapid industrial development and urbanization in China over the past three decades, PM2.5 pollution has become a severe environmental problem that threatens public health. Due to its unbalanced development and intrinsic topography features, the distribution of PM2.5 concentrations over China is spatially heterogeneous. In this study, we explore the spatiotemporal variations of PM2.5 pollution in China and four great urban areas from 1998 to 2014. A space-time Bayesian hierarchy model is employed to analyse PM2.5 pollution. The results show that a stable “3-Clusters” spatial PM2.5 pollution pattern has formed. The mean and 90% quantile of the PM2.5 concentrations in China have increased significantly, with annual increases of 0.279 μg/m3 (95% CI: 0.083−0.475) and 0.735 μg/m3 (95% CI: 0.261−1.210), respectively. The area with a PM2.5 pollution level of more than 70 μg/m3 has increased significantly, with an annual increase of 0.26 percentage points. Two regions in particular, the North China Plain and Sichuan Basin, are experiencing the largest amounts of PM2.5 pollution. The polluted areas, with a high local magnitude of more than 1.0 relative to the overall PM2.5 concentration, affect an area with a human population of 949 million, which corresponded to 69.3% of the total population in 2010. North and south differentiation occurs in the urban areas of the Jingjinji and Yangtze Delta, and circular and radial gradient differentiation occur in the urban areas of the Cheng-Yu and Pearl Deltas. The spatial heterogeneity of the urban Jingjinji group is the strongest. Eighteen cities located in the Yangtze Delta urban group, including Shanghai and Nanjing, have experienced high PM2.5 concentrations and faster local trends of increasing PM2.5. The percentage of exposure to PM2.5 concentrations greater than 70 μg/m3 and 100 μg/m3 is increasing significantly. PMID:27490557

  5. Source of Personal Exposure to PM2.5 among College Students in Beijing, China

    NASA Astrophysics Data System (ADS)

    Xie, Qiaorong; Zhu, Xianlei; Li, Xiang; Hui, Fan; Fu, Xianqiang; Zhang, Qiangbin

    2015-04-01

    The health risk from exposure to airborne particles arouses increasing public concern in Beijing, a megacity in China, where concentration of PM2.5 frequently exceeds the guideline values of World Health Organization (WHO). To investigate daily exposure to PM2.5, a personal exposure study was conducted for college students. The purpose of this study was to measure the daily PM2.5 personal exposures of students, to quantify the contributions of various microenvironments to personal exposure since students spend more than 85% of their time indoors, and to apportion the contributions of PM2.5 indoors origin and outdoor origin. In this work, a total of 320 paired indoor and outdoor PM2.5 samples were collected at eight types of microenvironments in both China University of Petroleum (suburban area) and Tsinghua University (urban area). The microenvironments were selected based on the time-activity diary finished by 1500 students from both universities. Simultaneously, the air exchange rate was measured in each microenvironment. PM2.5, elements, inorganic ions and polycyclic aromatic hydrocarbons in the samples were determined. The peak concentrations were observed in dinning halls, whereas PM2.5 in dormitories was the largest contributor to personal exposure because students spend more than half of a day there. Furthermore, source apportionment by positive matrix factorization (PMF) will be carried out to understand the source of personal exposure to PM2.5. Especially, efforts will be put on determing the contributions of primary combustion, secondary sulfate and organics, secondary nitrate, and mechanically generated PM, which present different infiltration behavior and are indoor PM2.5 of ambient origin, with help of air exchange rate data. The results would be benefit for refining the understanding of the contribution of PM2.5 of ambient (outdoor) origin to the daily PM2.5 personal exposures. Acknowledgments:This study has been funded by Beijing Municipal Commission

  6. Source identification of ambient PM 2.5 during summer inhalation exposure studies in Detroit, MI

    NASA Astrophysics Data System (ADS)

    Morishita, Masako; Keeler, Gerald J.; Wagner, James G.; Harkema, Jack R.

    Particulate air pollution is associated with cardiopulmonary morbidity and mortality in heavily populated urban centers of the United States. Because ambient fine particulate matter (aerodynamic diameter ⩽2.5 μm; PM 2.5) is a complex mixture resulting from multiple sources and variable atmospheric conditions, it is difficult to identify specific components of PM 2.5 that are responsible for adverse health effects. During four consecutive summers from 2000 to 2003 we characterized the ambient gaseous and PM 2.5 air quality in an urban southwest Detroit community where childhood asthma hospitalization rates are more than twice the statewide average. Both integrated and continuous PM measurements together with gaseous air pollution measurements were performed using a mobile air research facility, AirCARE1, in which concurrent toxicological studies were being conducted. Chemical and physical characterizations of PM 2.5 as well as receptor modeling using positive matrix factorization (PMF) were completed. Results from PMF indicated that six major sources contributed to the observed ambient PM 2.5 mass during the summer months. Primary sources included (1) coal combustion/secondary sulfate aerosol, (2) motor vehicle/urban road dust, (3) municipal waste incinerators, (4) oil combustion/refineries, (5) sewage sludge incinerators, and (6) iron/steel manufacturing. Although the contribution of the coal/secondary sulfate aerosol source was greater than other factors, increased levels of urban PM 2.5 from local combustion sources were also observed. In addition to characterization of ambient PM 2.5 and their sources in southwest Detroit, this paper discusses possible associations of ambient PM 2.5 from local combustion sources, specifically incinerator and refinery emissions and the observed adverse health effects during the inhalation exposure campaigns.

  7. PM2.5 Pollution in Eastern Coastal Provinces of China during winter

    NASA Astrophysics Data System (ADS)

    CAI, Z.; Jiang, F.

    2015-12-01

    Abstract: The area of eastern coastal provinces of China is one of the most developed regions in China. Previous studies of PM2.5 pollution were mainly focused on the Yangtze River Delta (YRD) and the Bejing-Tianjing-Heibei (BTH) region, which are respectively located in the north and south of this study area. In this study, we treated this area as a whole. Based on hourly PM2.5 concentrations of 55 cities located in this area and meteorological fields in China, we investigated the spatial and temporal variabilities of PM2.5 concentrations over the study area, and analyzed the relationships between PM2.5 concentrations and weather conditions. We found that the PM2.5 pollution did not only occur in the traditional focused regions, i.e., YRD and BTH, but also happened in the whole area. During winter, there were 49 cities with their mean concentrations exceeding the China's national standard (75 μg/m3), in which 12 cities' concentrations were greater than 150 μg/m3. The 12 cities are located in the southwest of Hebei and the west of Shandong provinces, including Shijiazhuang, Xingtai, Handan, Liaocheng, etc. The PM2.5 pollution in December was more serious than the other two months. In December, there were about one third of the whole 55 cities with their monthly mean concentrations exceeding 150μg/m3. From December to February, except in the north area of BTH, the mean concentrations had a decreasing trend. Inspecting into the weather conditions, we found that there were strong relationship between the high PM2.5 pollution and the weather condition. Generally, high PM2.5 pollution is corresponding to a stable weather condition, and low PM2.5 concentration is corresponding to a fast moving of cold anticyclone, indicating that the emissions of PM2.5 and its precursors in most area are too high that once the weather condition becomes stable, the pollution comes, specially in the south of Heibei and the west of Shandong areas. We also found that there were strong

  8. Lifting business process diagrams to 2.5 dimensions

    NASA Astrophysics Data System (ADS)

    Effinger, Philip; Spielmann, Johannes

    2010-01-01

    In this work, we describe our visualization approach for business processes using 2.5 dimensional techniques (2.5D). The idea of 2.5D is to add the concept of layering to a two dimensional (2D) visualization. The layers are arranged in a three-dimensional display space. For the modeling of the business processes, we use the Business Process Modeling Notation (BPMN). The benefit of connecting BPMN with a 2.5D visualization is not only to obtain a more abstract view on the business process models but also to develop layering criteria that eventually increase readability of the BPMN model compared to 2D. We present a 2.5D Navigator for BPMN models that offers different perspectives for visualization. Therefore we also develop BPMN specific perspectives. The 2.5D Navigator combines the 2.5D approach with perspectives and allows free navigation in the three dimensional display space. We also demonstrate our tool and libraries used for implementation of the visualizations. The underlying general framework for 2.5D visualizations is explored and presented in a fashion that it can easily be used for different applications. Finally, an evaluation of our navigation tool demonstrates that we can achieve satisfying and aesthetic displays of diagrams stating BPMN models in 2.5D-visualizations.

  9. An update on 2,5-diketopiperazines from marine organisms.

    PubMed

    Huang, Ri-Ming; Yi, Xiang-Xi; Zhou, Yuying; Su, Xiangdong; Peng, Yan; Gao, Cheng-Hai

    2014-12-01

    2,5-Diketopiperazines (2,5-DKPs) are an important category of structurally diverse cyclic dipeptides with prominent biological properties. These 2,5-DKPs have been obtained from a variety of natural resources, including marine organisms. Because of the increasing numbers and biological importance of these compounds, this review covers 90 marine originated 2,5-DKPs that were reported from 2009 to the first half-year of 2014. The review will focus on the structure characterizations, biological properties and proposed biosynthetic processes of these compounds. PMID:25532564

  10. The sensitivities of emissions reductions for the mitigation of UK PM2.5

    NASA Astrophysics Data System (ADS)

    Vieno, M.; Heal, M. R.; Williams, M. L.; Carnell, E. J.; Nemitz, E.; Stedman, J. R.; Reis, S.

    2016-01-01

    The reduction of ambient concentrations of fine particulate matter (PM2.5) is a key objective for air pollution control policies in the UK and elsewhere. Long-term exposure to PM2.5 has been identified as a major contributor to adverse human health effects in epidemiological studies and underpins ambient PM2.5 legislation. As a range of emission sources and atmospheric chemistry transport processes contribute to PM2.5 concentrations, atmospheric chemistry transport models are an essential tool to assess emissions control effectiveness. The EMEP4UK atmospheric chemistry transport model was used to investigate the impact of reductions in UK anthropogenic emissions of primary PM2.5, NH3, NOx, SOx or non-methane VOC on surface concentrations of PM2.5 in the UK for a recent year (2010) and for a future current legislation emission (CLE) scenario (2030). In general, the sensitivity to UK mitigation is rather small. A 30 % reduction in UK emissions of any one of the above components yields (for the 2010 simulation) a maximum reduction in PM2.5 in any given location of ˜ 0.6 µg m-3 (equivalent to ˜ 6 % of the modelled PM2.5). On average across the UK, the sensitivity of PM2.5 concentrations to a 30 % reduction in UK emissions of individual contributing components, for both the 2010 and 2030 CLE baselines, increases in the order NMVOC, NOx, SOx, NH3 and primary PM2.5; however there are strong spatial differences in the PM2.5 sensitivities across the UK. Consequently, the sensitivity of PM2.5 to individual component emissions reductions varies between area and population weighting. Reductions in NH3 have the greatest effect on area-weighted PM2.5. A full UK population weighting places greater emphasis on reductions of primary PM2.5 emissions, which is simulated to be the most effective single-component control on PM2.5 for the 2030 scenario. An important conclusion is that weighting corresponding to the average exposure indicator metric (using data from the 45

  11. Timing and conditions of metamorphism and melt crystallization in Greater Himalayan rocks, eastern and central Bhutan: insight from U-Pb zircon and monazite geochronology and trace-element analyses

    NASA Astrophysics Data System (ADS)

    Zeiger, K.; Gordon, S. M.; Long, S. P.; Kylander-Clark, A. R. C.; Agustsson, K.; Penfold, M.

    2015-05-01

    Within the eastern Himalaya in central and eastern Bhutan, Greater Himalayan (GH) rocks are interpreted to have been thickened by the Kakhtang thrust (KT). In order to understand the metamorphic and exhumation history of the GH and to evaluate the structural significance of the KT, zircon and monazite from twenty samples were analyzed by laser-ablation split-stream ICPMS. In eastern Bhutan, zircon and monazite from samples collected in the KT hanging wall revealed ca. 36-28 Ma metamorphism. Subsequently, the initiation of melt crystallization shows a trend with structural distance above the KT, with early melt crystallization (ca. 27 Ma) in the structurally highest samples and younger melt crystallization (ca. 16 Ma) for leucosomes within the KT zone. Melt crystallization was protracted and continued until ca. 14-13 Ma in both the KT hanging wall and the footwall. In comparison, in central Bhutan, two leucosomes revealed extended melt crystallization from ca. 31 to 19 Ma. The youngest zircon dates from samples exposed structurally above and below the KT are similar, indicating that the KT was not as significant of a structure as other fault systems to which it has been correlated. However, the younging trend in the initiation of melt crystallization with decreasing structural distance above the KT argues that progressive underplating of ductile material assisted in the initial emplacement of the GH unit in central and eastern Bhutan. The KT likely represents a minor shear zone that aided in this underplating process.

  12. Photochemistry Of 2,5-Diacyl-1, 4-Dimethylbenzenes

    NASA Technical Reports Server (NTRS)

    Meador, Michael A.

    1989-01-01

    Experiments described in report revealed potentially useful aspects of photochemistry of 2,5-dibenzoyl-1, 4-dimethylbenzene (DBX) and 2,5-diacetyl-1, 4-dimethylbenzene (DAX). Behavior of these compounds reminiscent of orthoalkylphenyl ketones, studied from similar perspective for more than two decades.

  13. 14 CFR Sec. 2-5 - Revenue and accounting practices.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Revenue and accounting practices. Sec. 2-5... General Accounting Provisions Sec. 2-5 Revenue and accounting practices. (a) Revenue accounting practices... physically verify the reliability of its passenger revenue accounting practice at least once each...

  14. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 2 2014-10-01 2014-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  15. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  16. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 2 2012-10-01 2012-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  17. 43 CFR 3861.2-5 - Amended mineral surveys.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 2 2013-10-01 2013-10-01 false Amended mineral surveys. 3861.2-5 Section... MANAGEMENT, DEPARTMENT OF THE INTERIOR MINERALS MANAGEMENT (3000) MINERAL PATENT APPLICATIONS Surveys and Plats § 3861.2-5 Amended mineral surveys. (a) Inasmuch as amended surveys are ordered only by...

  18. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE... in the affected area during this and future generations will be adequately protected...

  19. 10 CFR 960.5-2-5 - Environmental quality.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Environmental quality. 960.5-2-5 Section 960.5-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE... in the affected area during this and future generations will be adequately protected...

  20. Zircon SHRIMP U-Pb dating of metamorphic complexes in the conjunction of the Greater and Lesser Xing'an ranges, NE China: Timing of formation and metamorphism and tectonic implications

    NASA Astrophysics Data System (ADS)

    Miao, Laicheng; Zhang, Fuqin; Zhu, Mingshuai; Liu, Dunyi

    2015-12-01

    Metamorphic complexes, including the Luomahu, Xinkailing and Fengshuigouhe groups, are scattered in the conjunction of the Greater and the Lesser Xing'an ranges, NE China, and have long been interpreted to represent the Precambrian basement of the so-called "Xing'an" and "Songnen" blocks although reliable evidence is lacking. Thin-section examination and mineral assemblage indicate that the protoliths of these metamorphic rocks are mainly meta-sedimentary and meta-volcanic rocks and have experienced greenschist- to amphibolite-facies metamorphism and strong deformation. Zircon SHRIMP U-Pb dating results of the metamorphic complexes and associated pre- or syn-kinematic veins constrained the formation and metamorphic ages of the Luomahuo Group at 175 ± 3 Ma and 159 ± 3 Ma, the Xingkailing Group at 200 ± 2 Ma and 158 ± 3 Ma, and the Fengshuigouhe Group at between 230-310 Ma and 170 ± 3 Ma, respectively. Additionally, all these rocks contain some Late Paleozoic detrital or inherited zircons with ages between 290-390 Ma, but no Precambrian, even if Early Paleozoic, age information was detected from these metamorphic rocks. These new data suggest that the metamorphic complexes were formed during Mesozoic-Late Paleozoic period, rather than in Precambrian as previously inferred, and that all of them underwent metamorphism and deformation during Middle Jurassic between 170-160 Ma. Consequently, these metamorphic complexes are not basement rocks of the so-called Precambrian continental blocks. Instead, there are likely metamorphosed Late Paleozoic-Mesozoic accretionary complexes and/or arc terranes. These results, in combination with published data, illustrate an overall young trend from north to south in the tectonic evolution of the northern Xing'an region. Significantly, the Jurassic (170-160 Ma) metamorphism and deformation event firstly identified by this study from the metamorphic complexes likely recorded the coinstantaneous Mongol-Okhotsk collisional and

  1. Synthesis of 2,5-Dichloro-2,5-Dimethylhexane by an S[subscript N]1 Reaction

    ERIC Educational Resources Information Center

    Wagner, Carl E.; Marshall, Pamela A.

    2010-01-01

    This laboratory experiment was developed to provide a safe, economical, and effective way to instruct undergraduate organic chemistry students about the unimolecular nucleophilic substitution (S[subscript N]1) reaction. Students treat 2,5-dimethyl-2,5-hexanediol with excess concentrated hydrochloric acid to synthesize…

  2. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973–2013

    PubMed Central

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-01-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e−0.232x; R2 = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R2 = 0.5917, P < 0.05; R2 = 0.5426, P < 0.05); 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality. PMID:27031598

  3. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973-2013

    NASA Astrophysics Data System (ADS)

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-03-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e-0.232x R2 = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R2 = 0.5917, P < 0.05 R2 = 0.5426, P < 0.05) 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality.

  4. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973-2013.

    PubMed

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-03-31

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e(-0.232x); R(2) = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R(2) = 0.5917, P < 0.05; R(2) = 0.5426, P < 0.05); 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality.

  5. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973–2013

    NASA Astrophysics Data System (ADS)

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-03-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e‑0.232x R2 = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R2 = 0.5917, P < 0.05 R2 = 0.5426, P < 0.05) 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality.

  6. Fine particulate (PM2.5) dynamics during rapid urbanization in Beijing, 1973-2013.

    PubMed

    Han, Lijian; Zhou, Weiqi; Li, Weifeng

    2016-01-01

    PM2.5 has been given special concern in recent years when the air quality monitoring station started recording. However, long-term PM2.5 concentration dynamic analysis cannot be taken with the limited observations. We therefore estimated the PM2.5 concentration using meteorological visibility data in Beijing. We found that 71 ± 17% of PM10 were PM2.5, which contributed to visibility impairment (y = 332.26e(-0.232x); R(2) = 0.75, P < 0.05). We then reconstructed a time series of annual PM2.5 from 1973 to 2013, and examined its relationship with urbanization by indicators of population, gross domestic production (GDP), energy consumption, and number of vehicles. Concluded that 1) Meteorological conditions were not the major cause of PM2.5 increase from 1973 to 2013; 2) With population and GDP growth, PM2.5 increased significantly (R(2) = 0.5917, P < 0.05; R(2) = 0.5426, P < 0.05); 3) Intensive human activity could change air quality in a short period, as observed changes in the correlations of PM2.5 concentration with energy consumption and number of vehicles before and after 2004, respectively. The success of this research provides an easy way in reconstructing long-term PM2.5 concentration with limited PM2.5 observation and meteorological visibility, and insight the impact of urbanization on air quality. PMID:27031598

  7. CUMULATIVE PM2.5 EXPOSURE AND TELOMERE LENGTH IN WORKERS EXPOSED TO WELDING FUMES

    PubMed Central

    Wong, Jason Y. Y.; De Vivo, Immaculata; Lin, Xihong; Christiani, David C.

    2014-01-01

    Telomeres are genomic structures that reflect both mitotic history and biochemical trauma to the genome. Metals inherent in fine particulate matter (PM2.5) were shown to be genotoxic via oxidative damage. However, few studies investigated the induction time of cumulative PM2.5 exposure on telomere length in a longitudinal setting. Therefore, the purpose of this study was to assess the association between occupational PM2.5 exposure in various time windows and telomere length. The study population consisted of 48 boilermakers and the follow-up period was 8 yr. The main exposures were cumulative occupational PM2.5 in the month, year, and career prior to each blood draw, assessed via work history questionnaires and area air measures. Repeated telomere length measurements from leukocytes were assessed via real-time quantitative polymerase chain reaction (qPCR). Analysis was performed using linear mixed models controlling for confounders and white blood cell differentials. Cumulative PM2.5 exposure was treated continuously and categorized into quartiles, in separate analyses. At any follow-up time, for each milligram per cubic meter per hour increase in cumulative PM2.5 exposure in the prior month, there was a statistically significant decrease in relative telomere length of −0.04 units. When categorizing the exposure into quartiles, there was a significant negative association between telomere length and highest quartile of cumulative PM2.5 exposure in the prior month (−0.16). These findings suggest that genomic trauma to leukocyte telomeres was more consistent with recent occupational PM2.5 exposure, as opposed to cumulative exposure extending into the distant past. PMID:24627998

  8. Identification of potential source areas for elevated PM2.5, nitrate and sulfate concentrations

    NASA Astrophysics Data System (ADS)

    Heo, Jongbae; McGinnis, Jerome E.; de Foy, Benjamin; Schauer, James J.

    2013-06-01

    Extreme events or episodes of ambient fine particulate matter (PM2.5), in which daily mass concentrations are substantially higher than annual averages, have been frequently observed in southern Wisconsin, US. Determining the cause of events has been a great challenge to local governments responsible for protecting public health and complying with the 24-h PM2.5 standard. This study analyzed air parcel movements originating from emission source areas, and trends in PM2.5 concentrations in order to determine the important factors involved in elevated PM2.5 episodes in the region. A single backward trajectory analysis coupled with PM2.5 concentrations observed at Federal Reference Method Network (FRM) sites in Madison, Milwaukee and Waukesha; and nitrate and sulfate concentrations monitored at a Chemical Speciation Network (CSN) site in Milwaukee, Wisconsin, from 2002 to 2010 were examined. The PM2.5 concentrations from the FRM showed the total PM2.5 mass during the episodes were higher in Madison than in Milwaukee and Waukesha, while annual average concentrations were lower in Madison. However, the temporal trend in frequency of elevated PM2.5 episodes was remarkably similar across sites during the entire study period and high frequency episodes occurring from 2005 to 2007. Residence time analysis of backward trajectories calculated for all recorded data indicated episode changes were mainly driven by year-to-year variations of air mass movements originating in high emissions areas. Potential Source Contribution Function (PSCF) results showed the extreme events of PM2.5 occurred during times when trajectories passed over ammonia emissions hotspots as well as large stationary emissions. Enhanced nitrate and sulfate concentrations which were the major episode components were strongly influenced by air masses trajectories originating from the Ohio River Valley and adjacent states.

  9. Unfolding ESIPT in Bis-2,5-(2-benzoxazolyl) Hydroquinone and 2,5-Bis(benzo[d]oxazol-2-yl)-4-methoxyphenol: a Comprehensive Computational Approach.

    PubMed

    Jadhav, Manoj M; Rhyman, Lydia; Ramasami, Ponnadurai; Sekar, Nagaiyan

    2016-07-01

    The photo-physical behaviour of bis-2,5-(2-benzoxazolyl) hydroquinone and 2,5-bis (benzo[d]oxazol-2-yl)-4-methoxyphenol was studied using the Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT). All the possible rotamers were optimized to obtain global minimum optimized structure. The theoretical absorption and emission values of rotamers estimated by using TD-DFT [TD-B3LYP/6-31G(d)] are in good agreement with experimental absorption and emission wavelengths. Based on the absorption values, the contribution of respective rotamer is determined theoretically.

  10. Comparison of how ambient PMc and PM2.5 influence the inflammatory potential

    PubMed Central

    Ferguson, Matthew D.; Migliaccio, Chris; Ward, Tony

    2014-01-01

    Airborne particulate matter (PM) is one of six criteria air pollutants currently regulated by the U.S. Environmental Protection Agency (EPA), with existing ambient standards for PM2.5 and PM10. Currently there are no health-based regulations for the size fraction between 2.5 and 10 μm, commonly known as the coarse fraction (PMc). The present study investigates current gaps in knowledge for PMc including exposure toxicity and PM ratios (PMc:PM2.5) in PM10. Throughout the world, all three PM size fractions have been shown to be associated with adverse impacts. Recent studies have shown that PMc can be more detrimental to susceptible populations when directly compared to PM2.5, and that the PMc fraction in PM10 can account for the majority of the inflammatory response from PM10 exposure. In our studies we utilized a bone marrow-derived mouse macrophage in vitro system to compare the inflammatory potential of PMc, PM2.5, and mixtures of the two. The result was a linear increase in interleukin(IL) −1β with increasing levels of exposure to winter and summer PMc, as compared to PM2.5, which exhibited logarithmic growth. Also, exposure to PM10 as a function of PM2.5 and PMc mass ratios showed that IL-1β and TNF-α levels increased synergistically with a greater burden of PMc. Endotoxin content in the PM did not correlate with these results, suggesting that other activators in PMc are likely responsible for activating the NF-κB pathway and the inflammasome. PMID:24304303

  11. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  12. 41 CFR 51-2.5 - Committee decision.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Contracts COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED 2-COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED § 51-2.5 Committee decision. The Committee considers...

  13. General 2.5 power law of metallic glasses.

    PubMed

    Zeng, Qiaoshi; Lin, Yu; Liu, Yijin; Zeng, Zhidan; Shi, Crystal Y; Zhang, Bo; Lou, Hongbo; Sinogeikin, Stanislav V; Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Yang, Wenge; Wang, Weihua; Sheng, Hongwei; Mao, Ho-Kwang; Mao, Wendy L

    2016-02-16

    Metallic glass (MG) is an important new category of materials, but very few rigorous laws are currently known for defining its "disordered" structure. Recently we found that under compression, the volume (V) of an MG changes precisely to the 2.5 power of its principal diffraction peak position (1/q1). In the present study, we find that this 2.5 power law holds even through the first-order polyamorphic transition of a Ce68Al10Cu20Co2 MG. This transition is, in effect, the equivalent of a continuous "composition" change of 4f-localized "big Ce" to 4f-itinerant "small Ce," indicating the 2.5 power law is general for tuning with composition. The exactness and universality imply that the 2.5 power law may be a general rule defining the structure of MGs. PMID:26831105

  14. General 2.5 power law of metallic glasses

    PubMed Central

    Zeng, Qiaoshi; Lin, Yu; Liu, Yijin; Zeng, Zhidan; Shi, Crystal Y.; Zhang, Bo; Lou, Hongbo; Sinogeikin, Stanislav V.; Kono, Yoshio; Kenney-Benson, Curtis; Park, Changyong; Yang, Wenge; Wang, Weihua; Sheng, Hongwei; Mao, Ho-kwang; Mao, Wendy L.

    2016-01-01

    Metallic glass (MG) is an important new category of materials, but very few rigorous laws are currently known for defining its “disordered” structure. Recently we found that under compression, the volume (V) of an MG changes precisely to the 2.5 power of its principal diffraction peak position (1/q1). In the present study, we find that this 2.5 power law holds even through the first-order polyamorphic transition of a Ce68Al10Cu20Co2 MG. This transition is, in effect, the equivalent of a continuous “composition” change of 4f-localized “big Ce” to 4f-itinerant “small Ce,” indicating the 2.5 power law is general for tuning with composition. The exactness and universality imply that the 2.5 power law may be a general rule defining the structure of MGs. PMID:26831105

  15. Fine particulate matter (PM2.5) in China at a city level

    PubMed Central

    Zhang, Yan-Lin; Cao, Fang

    2015-01-01

    This study presents one of the first long term datasets including a statistical summary of PM2.5 concentrations obtained from one-year monitoring in 190 cities in China. We found only 25 out of 190 cities could meet the National Ambient Air Quality Standards of China, and the population-weighted mean of PM2.5 in Chinese cities are 61 μg/m3, ~3 times as high as global population-weighted mean, highlighting a high health risk. PM2.5 concentrations are generally higher in north than in south regions due to relative large PM emissions and unfavorable meteorological conditions for pollution dispersion. A remarkable seasonal variability of PM2.5 is observed with the highest during the winter and the lowest during the summer. Due to the enhanced contributions from dust particles and open biomass burning, high PM2.5 abundances are also found in the spring (in Northwest and West Central China) and autumn (in East China), respectively. In addition, we found the lowest and highest PM2.5 often occurs in the afternoon and evening hours, respectively, associated with daily variation of the boundary layer depth and anthropogenic emissions. The diurnal distribution of the PM2.5-to-CO ratio consistently displays a pronounced peak during the afternoon periods, reflecting a significant contribution of secondary PM formation. PMID:26469995

  16. Stereochemistry of 2',5' nucleic acids and their constituents.

    PubMed

    Premraj, B J; Yathindra, N

    1998-10-01

    Shape and dimension of the preferred nucleotide repeats in nucleic acids are found to depend on whether the sugar-phosphate linkage is of 2',5' or 3',5' type. It is shown that a nucleotide which is "compact" in 3',5' nucleic acids is rendered "extended" and vice versa for a given sugar pucker. It is interesting that this feature is accompanied by a switch in the preferred sugar ring conformation in 3',5' and 2',5' nucleic acids. 3' ribose and 3' deoxyribose rings (in 2',5' linkages) tend to favour C2' endo and C3' endo puckers respectively in contrast to C3' endo and C2' endo puckers favored by 2' ribose and 2' deoxyribose sugars (in 3',5' linkages). The distinguishable features between the nucleotide repeats of 3',5' and 2',5' nucleic acids need to be recognised while discussing their structural properties, as well as those of a variety of complexes that could be formed involving 2',5' and 3',5' strands of DNA and RNA. Ability and stability, or lack of them, for formation of a specific combination of these complexes may be directly related to the stereochemical constraints imposed as a consequence of conformationally homogeneous or heterogeneous nature of the repeating nucleotides of the complexing chains. As a first step towards delineating stereochemical features that distinguish 2',5' nucleic acids from their naturally occurring isomer A and B type helices have been modelled using the new concept of "compact" and "extended" nucleotide repeat that seemingly unifies helix generation of both types of linkages. Helical models for 2',5' RNA with "dinucleotide" repeat based on the crystal structure of 2',5' ApU have also been obtained.

  17. Quantifying PM2.5-meteorology sensitivities in a global climate model

    NASA Astrophysics Data System (ADS)

    Westervelt, D. M.; Horowitz, L. W.; Naik, V.; Tai, A. P. K.; Fiore, A. M.; Mauzerall, D. L.

    2016-10-01

    Climate change can influence fine particulate matter concentrations (PM2.5) through changes in air pollution meteorology. Knowledge of the extent to which climate change can exacerbate or alleviate air pollution in the future is needed for robust climate and air pollution policy decision-making. To examine the influence of climate on PM2.5, we use the Geophysical Fluid Dynamics Laboratory Coupled Model version 3 (GFDL CM3), a fully-coupled chemistry-climate model, combined with future emissions and concentrations provided by the four Representative Concentration Pathways (RCPs). For each of the RCPs, we conduct future simulations in which emissions of aerosols and their precursors are held at 2005 levels while other climate forcing agents evolve in time, such that only climate (and thus meteorology) can influence PM2.5 surface concentrations. We find a small increase in global, annual mean PM2.5 of about 0.21 μg m-3 (5%) for RCP8.5, a scenario with maximum warming. Changes in global mean PM2.5 are at a maximum in the fall and are mainly controlled by sulfate followed by organic aerosol with minimal influence of black carbon. RCP2.6 is the only scenario that projects a decrease in global PM2.5 with future climate changes, albeit only by -0.06 μg m-3 (1.5%) by the end of the 21st century. Regional and local changes in PM2.5 are larger, reaching upwards of 2 μg m-3 for polluted (eastern China) and dusty (western Africa) locations on an annually averaged basis in RCP8.5. Using multiple linear regression, we find that future PM2.5 concentrations are most sensitive to local temperature, followed by surface wind and precipitation. PM2.5 concentrations are robustly positively associated with temperature, while negatively related with precipitation and wind speed. Present-day (2006-2015) modeled sensitivities of PM2.5 to meteorological variables are evaluated against observations and found to agree reasonably well with observed sensitivities (within 10-50% over the

  18. Affinity labeling of (2'-5')-oligoadenylate-activated endonuclease with (/sup 32/P)-2', 5'A and its analogs

    SciTech Connect

    Saarma, M.Y.; Gordon, J.; Minks, M.A.

    1985-09-01

    This paper examines the role interferons play in the origin of the antiviral state of cells and in the inhibition of virus reproduction. Treatment of cells with interferon induces the synthesis of a whole series of proteins. For affinity labeling of 2', 5'A-dependent endoribonuclease, the authors synthesized P-32 labeled 2; 5'A by two methods. Results of the investigation show that the most probable candidate for 2', 5'A-dependent endoribonuclease is the protein with molecular weight 80,000. The role of the other two proteins is still unknown.

  19. Linking climate and air quality over Europe: effects of meteorology on PM2.5 concentrations

    NASA Astrophysics Data System (ADS)

    Megaritis, A. G.; Fountoukis, C.; Charalampidis, P. E.; Denier van der Gon, H. A. C.; Pilinis, C.; Pandis, S. N.

    2014-09-01

    The effects of various meteorological parameters such as temperature, wind speed, absolute humidity, precipitation and mixing height on PM2.5 concentrations over Europe were examined using a three-dimensional chemical transport model, PMCAMx-2008. Our simulations covered three periods, representative of different seasons (summer, winter, and fall). PM2.5 appears to be more sensitive to temperature changes compared to the other meteorological parameters in all seasons. PM2.5 generally decreases as temperature increases, although the predicted changes vary significantly in space and time, ranging from -700 ng m-3 K-1 (-8% K-1) to 300 ng m-3 K-1 (7% K-1). The predicted decreases of PM2.5 are mainly due to evaporation of ammonium nitrate, while the higher biogenic emissions and the accelerated gas-phase reaction rates increase the production of organic aerosol (OA) and sulfate, having the opposite effect on PM2.5. The predicted responses of PM2.5 to absolute humidity are also quite variable, ranging from -130 ng m-3 %-1 (-1.6% %-1) to 160 ng m-3 %-1 (1.6% %-1) dominated mainly by changes in inorganic PM2.5 species. An increase in absolute humidity favors the partitioning of nitrate to the aerosol phase and increases the average PM2.5 during summer and fall. Decreases in sulfate and sea salt levels govern the average PM2.5 response to humidity during winter. A decrease of wind speed (keeping the emissions constant) increases all PM2.5 species (on average 40 ng m-3 %-1) due to changes in dispersion and dry deposition. The wind speed effects on sea salt emissions are significant for PM2.5 concentrations over water and in coastal areas. Increases in precipitation have a negative effect on PM2.5 (decreases up to 110 ng m-3 %-1) in all periods due to increases in wet deposition of PM2.5 species and their gas precursors. Changes in mixing height have the smallest effects (up to 35 ng m-3 %-1) on PM2.5 . Regarding the relative importance of each of the meteorological

  20. Linking climate and air quality over Europe: effects of meteorology on PM2.5 concentrations

    NASA Astrophysics Data System (ADS)

    Megaritis, A. G.; Fountoukis, C.; Charalampidis, P. E.; Denier van der Gon, H. A. C.; Pilinis, C.; Pandis, S. N.

    2014-04-01

    The effects of various meteorological parameters such as temperature, wind speed, absolute humidity, precipitation and mixing height on PM2.5 concentrations over Europe were examined using a three-dimensional chemical transport model, PMCAMx-2008. Our simulations covered three periods, representative of different seasons (summer, winter, and fall). PM2.5 appears to be more sensitive to temperature changes compared to the other meteorological parameters in all seasons. PM2.5 generally decreases as temperature increases, although the predicted changes vary significantly in space and time, ranging from -700 ng m-3 K-1 (-8% K-1) to 300 ng m-3 K-1 (7% K-1). The predicted decreases of PM2.5 are mainly due to evaporation of ammonium nitrate, while the higher biogenic emissions and the accelerated gas-phase reaction rates increase the production of organic aerosol (OA) and sulfate, having the opposite effect on PM2.5. The predicted responses of PM2.5 to absolute humidity are also quite variable, ranging from -130 ng m-3%-1 (-1.6% %-1) to 160 ng m-3 %-1 (1.6% %-1) dominated mainly by changes in inorganic PM2.5 species. An increase in absolute humidity favors the partitioning of nitrate to the aerosol phase and increases the average PM2.5 during summer and fall. Decreases in sulfate and sea salt levels govern the average PM2.5 response to humidity during winter. A decrease of wind speed (keeping constant the emissions) increases all PM2.5 species (on average 40 ng m-3 %-1) due to changes in dispersion and dry deposition. The wind speed effects on sea salt emissions are significant for PM2.5 concentrations over water and in coastal areas. Increases in precipitation have a negative effect on PM2.5 (decreases up to 110 ng m-3 %-1) in all periods due to increases in wet deposition of PM2.5 species and their gas precursors. Changes in mixing height have the smallest effects (up to 35 ng m-3 %-1) on PM2.5. Regarding the relative importance of each of the meteorological parameters

  1. Endotoxin in fine (PM 2.5) and coarse (PM 2.5-10) particle mass of ambient aerosols. A temporo-spatial analysis

    NASA Astrophysics Data System (ADS)

    Heinrich, Joachim; Pitz, Mike; Bischof, Wolfgang; Krug, Norbert; Borm, Paul J. A.

    Objectives: We collected fine (PM 2.5) and coarse (PM 2.5-10) particulate matter fractions in two areas ˜80 km apart and measured soluble endotoxin concentrations in both particle fractions. Here we report on temporo-spatial variation of endotoxin content in the collected particles. Methods: Dichotomous Anderson samplers were used to collect 21 weekly samples of PM 2.5 and PM 2.5-10 in both towns from January to June 2002. Each Teflon filter was water extracted and endotoxin was measured by a chromogenic Limulus Amoebocyte Lysate method. Endotoxin concentrations were expressed per mg of fine or mg of coarse mass and per sampled air volume (m 3). Results: For both cities, the mean endotoxin content in PM 2.5 was 1.2 EU mg -1; however the endotoxin content in the coarse fraction was ˜10 times higher compared to the fine mass fractions. Although endotoxin content is highly variable over time, a good correlation was observed between the two town sites for both fine ( r=0.85) and coarse PM ( r=0.88). The fluctuations of weekly endotoxin means were high in both areas suggesting a strong temporal dependence on particle source and composition. The endotoxin content in particles collected during May and June were two to four times higher than concentrations measured during the winter and early spring weeks. Conclusions: Ambient airborne endotoxin concentrations were detected in coarse and fine particle fraction, but 10-fold higher in the coarse PM. The strong seasonality and the week to week fluctuation of endotoxin content in PM indicate different biologic PM properties which might affect results of time series studies on short-term effects as well as in vitro studies and human exposure studies.

  2. Fine particulate matter components and mortality in Greater Houston: Did the risk reduce from 2000 to 2011?

    PubMed

    Liu, Suyang; Zhang, Kai

    2015-12-15

    Fine particulate matter (less than 2.5μm in aerodynamic diameter; PM2.5) pollution poses a major environmental threat in Greater Houston due to rapid economic growth and the numerous PM2.5 sources including ports, vehicles, and the largest petrochemical industry in the United States (U.S.). Our objectives were to estimate the short-term associations between the PM2.5 components and mortality during 2000-2011, and evaluate whether these associations have changed over time. A total of 333,317 deaths were included in our assessment, with an average of 76 deaths per day. We selected 17 PM2.5 components from the U.S. Environmental Protection Agency's Chemical Speciation Network, and then applied Poisson regression models to assess the associations between the PM2.5 components and mortality. Additionally, we repeated our analysis for two consecutive periods: 2000-2005 and 2006-2011. Interquartile range increases in ammonium (0.881μg/m(3)), nitrate (0.487μg/m(3)), sulfate (2.245μg/m(3)), and vanadium (0.004μg/m(3)) were associated with an increased risk in mortality of 0.69% (95% confidence interval (CI): 0.26, 1.12%), 0.38% (95% CI: 0.11, 0.66%), 0.61% (95% CI: 0.15, 1.06%), and 0.58% (95% CI: 0.12, 1.04%), respectively. Seasonal analysis suggested that the associations were strongest during the winter months. The association between PM2.5 mass and mortality decreased during 2000-2011, however, the PM2.5 components showed no notable changes in mortality risk over time. Our study indicates that the short-term associations between PM2.5 and mortality differ across the PM2.5 components and suggests that future air pollution control measures should not only focus on mass but also pollutant sources.

  3. Black Carbon as an Additional Indicator of the Adverse Health Effects of Airborne Particles Compared with PM10 and PM2.5

    PubMed Central

    Hoek, Gerard; Simic-Lawson, Milena; Fischer, Paul; van Bree, Leendert; ten Brink, Harry; Keuken, Menno; Atkinson, Richard W.; Anderson, H. Ross; Brunekreef, Bert; Cassee, Flemming R.

    2011-01-01

    Background: Current air quality standards for particulate matter (PM) use the PM mass concentration [PM with aerodynamic diameters ≤ 10 μm (PM10) or ≤ 2.5 μm (PM2.5)] as a metric. It has been suggested that particles from combustion sources are more relevant to human health than are particles from other sources, but the impact of policies directed at reducing PM from combustion processes is usually relatively small when effects are estimated for a reduction in the total mass concentration. Objectives: We evaluated the value of black carbon particles (BCP) as an additional indicator in air quality management. Methods: We performed a systematic review and meta-analysis of health effects of BCP compared with PM mass based on data from time-series studies and cohort studies that measured both exposures. We compared the potential health benefits of a hypothetical traffic abatement measure, using near-roadway concentration increments of BCP and PM2.5 based on data from prior studies. Results: Estimated health effects of a 1-μg/m3 increase in exposure were greater for BCP than for PM10 or PM2.5, but estimated effects of an interquartile range increase were similar. Two-pollutant models in time-series studies suggested that the effect of BCP was more robust than the effect of PM mass. The estimated increase in life expectancy associated with a hypothetical traffic abatement measure was four to nine times higher when expressed in BCP compared with an equivalent change in PM2.5 mass. Conclusion: BCP is a valuable additional air quality indicator to evaluate the health risks of air quality dominated by primary combustion particles. PMID:21810552

  4. Personal exposures to PM 2.5 and their relationships with microenvironmental concentrations

    NASA Astrophysics Data System (ADS)

    Lim, Soogil; Kim, Jeonghoon; Kim, Taehyun; Lee, Kiyoung; Yang, Wonho; Jun, Sangil; Yu, Seungdo

    2012-02-01

    Personal exposure to particulate matter of aerodynamic diameters less than 2.5 μm (PM 2.5) can be affected by various factors. The purpose of this study was to determine the impact of activity pattern and the contribution of each microenvironment to personal PM 2.5 exposure. Technicians carried a nephelometer for PM 2.5 while engaging in scripted time location activities. The scripted activities of 10 different population groups were based on time activity patterns of the Seoul population in Korea. A total of 58 daily PM 2.5 personal exposures were available for analysis. The average PM 2.5 personal exposure was 19.8 ± 15.3 μg m -3. The average personal exposure of each population group ranged from 9.8 to 43.1 μg m -3. High peak and average concentrations were observed in restaurants and bars; such high concentrations were due to secondhand smoke and cooking with charcoal on tables. The residential indoor level of the nine microenvironments was the largest contributor to personal exposure. The contributions from residential indoor, non-residential indoor, transportation, and outdoor levels were 36.2%, 53.4%, 6.7%, and 3.7%, respectively. The contributions of microenvironments varied among population groups; these variations suggest that the impact of activity pattern on personal exposure is significant.

  5. Determination of 2,5-toluylenediamine (2,5-TDA) and aromatic amines in urine after personal application of hair dyes: kinetics and doses.

    PubMed

    Schettgen, Thomas; Heinrich, K; Kraus, T; Gube, Monika

    2011-02-01

    The personal use of hair dye products is currently under discussion due to the potentially increased risk of bladder cancer among long-time users described in epidemiological literature. In order to investigate the dermal absorption of aromatic diamines as well as aromatic amines possibly present as contaminants in hair dye formulations, we conducted a biomonitoring study under real-life conditions and calculated kinetics and doses for the urinary excretion. Urine samples of two female subjects were collected for a time period of 48 h after personal application of a hair dye cream and analysed for aromatic diamines as well as o-toluidine and 4-aminobiphenyl using highly specific GC/MS-methods. 2,5-Toluylenediamine (2,5-TDA) as active ingredient of hair dyes is rapidly absorbed dermally. After a distribution phase of 12 h, 2,5-TDA is excreted with a half-time of 8 h. Excretion was 90% complete within 24 h after application. The doses of 2,5-TDA excreted within 48 h were 700 μg for application of a brown-reddish hair dye cream and 1.5 mg for the application of a brown-black hair dye cream. Urinary 4-aminobiphenyl as well as contaminations with other aromatic diamines were not detectable in our study. Due to the artifactual formation of o-toluidine in the presence of high concentrations of urinary 2,5-TDA, our results could not prove an increased internal exposure of humans to carcinogenic amines after personal application of hair dyes.

  6. BLOCKAGE 2.5 user`s manual

    SciTech Connect

    Rao, D.V.; Brideau, J.; Shaffer, C.; Souto, F.; Bernahl, W.

    1996-12-01

    The BLOCKAGE 2.5 code described in this User`s Manual was developed by the US Nuclear Regulatory Commission (NRC) as a tool to evaluate licensee compliance with NRC Bulletin 96-03, ``Potential Plugging of Emergency Core Cooling Suction Strainers by Debris in Boiling Water Reactors.`` As such, BLOCKAGE 2.5 provides a generalized framework into which a user can input plant-specific and insulation-specific data for performing analyses in accordance with Regulatory Guide 1.82, Rev. 2. This user`s manual describes the capabilities of BLOCKAGE 2.5 along with a description of the graphics user`s interface provided for data entry. Each input/output dialog is described in detail along with special considerations related to developing and executing BLOCKAGE. Also, several sample problems are provided such that user can easily modify them to suit a particular plant of interest. The models used in BLOCKAGE 2.5 and their validation are presented in the accompanying NUREG/CR-6371. The BLOCKAGE models were designed to be parametric in nature, allowing the user flexibility to examine the impact of several modeling assumptions and to conduct sensitivity analyses. As a result, BLOCKAGE 2.5 results are known to be very sensitive to the user provided input. It is therefore strongly recommended that users become thoroughly familiar with BLOCKAGE models and their limitations as described in NUREG/CR-6224.

  7. Rat lung response to ozone and fine particulate matter (PM2.5) exposures.

    PubMed

    Wang, Guanghe; Zhao, Jinzhuo; Jiang, Rongfang; Song, Weimin

    2015-03-01

    Exposure to different ambient pollutants maybe more toxic to lung than exposure to a single pollutant. In this study, we discussed the inflammation and oxidative stress responses of rat lung caused by ozone and PM2.5 versus that of rats exposed to saline, ozone, or single PM2.5 . Wistar rats inhaled 0.8 ppm ozone or air for 4 h and then placed in air for 3 h following intratracheal instillation with 0, 0.2 (low dose), 0.8 (medium dose), 3.2 (high dose) mg/rat PM2.5 dissolved in sterile saline (0.25 mL/rat), repeated twice per week for 3 weeks, the cumulative doses of PM2.5 in animals were 1.2, 4.8, and 19.2 mg. Rats were sacrificed 24 h after the last (sixth) exposure. The collected bronchoalveolar lavage fluid (BALF) was analyzed for inflammatory cells and cytokines. Lung tissues were processed for light microscopic and transmission electron microscopic (TEM) examinations. Results showed that total cell number in BALF of PM2.5 -exposed groups were higher than control (p < 0.05). PM2.5 instillation caused dose-trend increase in tumor necrosis factor alpha (TNF-α), interleukin-6, lactate dehydrogenase, and total protein of BALF. Exposure to ozone alone only caused TNF-α significant change in above-mentioned indicators of lung injury. On the other hand, ozone could enhance PM2.5-induced inflammatory changes and pathological characters in rat lungs. SOD and GSH-Px activities in lung were reduced in PM2.5-exposed rats with and without prior ozone exposure compared to control. To determine whether the PM2.5 and ozone affect endothelium system, iNOS, eNOS, and ICAM-1 mRNA levels in lung were analyzed by real-time PCR. These data demonstrated that inflammation and oxidative stress were involved in toxicology mechanisms of PM2.5 in rat lung and ozone potentiated these effects induced by PM2.5. These results have implications for understanding the pulmonary effects induced by ozone and PM2.5.

  8. Multisensor Arrays for Greater Reliability and Accuracy

    NASA Technical Reports Server (NTRS)

    Immer, Christopher; Eckhoff, Anthony; Lane, John; Perotti, Jose; Randazzo, John; Blalock, Norman; Ree, Jeff

    2004-01-01

    Arrays of multiple, nominally identical sensors with sensor-output-processing electronic hardware and software are being developed in order to obtain accuracy, reliability, and lifetime greater than those of single sensors. The conceptual basis of this development lies in the statistical behavior of multiple sensors and a multisensor-array (MSA) algorithm that exploits that behavior. In addition, advances in microelectromechanical systems (MEMS) and integrated circuits are exploited. A typical sensor unit according to this concept includes multiple MEMS sensors and sensor-readout circuitry fabricated together on a single chip and packaged compactly with a microprocessor that performs several functions, including execution of the MSA algorithm. In the MSA algorithm, the readings from all the sensors in an array at a given instant of time are compared and the reliability of each sensor is quantified. This comparison of readings and quantification of reliabilities involves the calculation of the ratio between every sensor reading and every other sensor reading, plus calculation of the sum of all such ratios. Then one output reading for the given instant of time is computed as a weighted average of the readings of all the sensors. In this computation, the weight for each sensor is the aforementioned value used to quantify its reliability. In an optional variant of the MSA algorithm that can be implemented easily, a running sum of the reliability value for each sensor at previous time steps as well as at the present time step is used as the weight of the sensor in calculating the weighted average at the present time step. In this variant, the weight of a sensor that continually fails gradually decreases, so that eventually, its influence over the output reading becomes minimal: In effect, the sensor system "learns" which sensors to trust and which not to trust. The MSA algorithm incorporates a criterion for deciding whether there remain enough sensor readings that

  9. Principal component analysis optimization of a PM2.5 land use regression model with small monitoring network.

    PubMed

    Olvera, Hector A; Garcia, Mario; Li, Wen-Whai; Yang, Hongling; Amaya, Maria A; Myers, Orrin; Burchiel, Scott W; Berwick, Marianne; Pingitore, Nicholas E

    2012-05-15

    The use of land-use regression (LUR) techniques for modeling small-scale variations of intraurban air pollution has been increasing in the last decade. The most appealing feature of LUR techniques is the economical monitoring requirements. In this study, principal component analysis (PCA) was employed to optimize an LUR model for PM2.5. The PM2.5 monitoring network consisted of 13 sites, which constrained the regression model to a maximum of one independent variable. An optimized surrogate of vehicle emissions was produced by PCA and employed as the predictor variable in the model. The vehicle emissions surrogate consisted of a linear combination of several traffic variables (e.g., vehicle miles traveled, speed, traffic demand, road length, and time) obtained from a road network used for traffic modeling. The vehicle-emissions surrogate produced by the PCA had a predictive capacity greater (R2=.458) than the traffic variable, Traffic Demand summarized for a 1 km buffer, with best predictive capacity (R2=.341). The PCA-based method employed in this study was effective at increasing the fit of an ordinary LUR model by optimizing the utilization of a PM2.5 dataset from small-n monitoring network. In general, the method used can contribute to LUR techniques in two major ways: 1) by improving the predictive power of the input variable, by substituting a principal component for a single variable and 2) by creating an orthogonal set of predictor variables, and thus fulfilling the no colinearity assumption of the linear regression methods. The proposed PCA method, should be universally applicable to LUR methods and will expand their economical attractiveness.

  10. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2001-10-31

    This interim report summarizes detailed findings and conclusions drawn from evaluations of data obtained from the operation of ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the Upper Ohio River Valley region through the collection of chemically resolved or speciated data. A summary of the sampling activities, sample analyses and the correlation and interpretation of data acquired from February 1999 through March of 2001 are reported. Mass and speciated data from urban and rural sources are compared and seasonal variations in PM{sub 2.5} distribution are also examined. Correlations between meteorological parameters and total PM{sub 2.5} mass are also presented.

  11. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2002-10-31

    This interim report summarizes detailed findings and conclusions drawn from evaluations of data obtained from the operation of ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the Upper Ohio River Valley region through the collection of chemically resolved or speciated data. A summary of the sampling activities, sample analyses and the correlation and interpretation of data acquired from February 1999 through March of 2001 are reported. Mass and speciated data from urban and rural sources are compared and seasonal variations in PM{sub 2.5} distribution are also examined. Correlations between meteorological parameters and total PM{sub 2.5} mass are also presented.

  12. 2.5D dictionary learning based computed tomography reconstruction

    NASA Astrophysics Data System (ADS)

    Luo, Jiajia; Eri, Haneda; Can, Ali; Ramani, Sathish; Fu, Lin; De Man, Bruno

    2016-05-01

    A computationally efficient 2.5D dictionary learning (DL) algorithm is proposed and implemented in the model- based iterative reconstruction (MBIR) framework for low-dose CT reconstruction. MBIR is based on the minimization of a cost function containing data-fitting and regularization terms to control the trade-off between data-fidelity and image noise. Due to the strong denoising performance of DL, it has previously been considered as a regularizer in MBIR, and both 2D and 3D DL implementations are possible. Compared to the 2D case, 3D DL keeps more spatial information and generates images with better quality although it requires more computation. We propose a novel 2.5D DL scheme, which leverages the computational advantage of 2D-DL, while attempting to maintain reconstruction quality similar to 3D-DL. We demonstrate the effectiveness of this new 2.5D DL scheme for MBIR in low-dose CT. By applying the 2D DL method in three different orthogonal planes and calculating the sparse coefficients accordingly, much of the 3D spatial information can be preserved without incurring the computational penalty of the 3D DL method. For performance evaluation, we use baggage phantoms with different number of projection views. In order to quantitatively compare the performance of different algorithms, we use PSNR, SSIM and region based standard deviation to measure the noise level, and use the edge response to calculate the resolution. Experimental results with full view datasets show that the different DL based algorithms have similar performance and 2.5D DL has the best resolution. Results with sparse view datasets show that 2.5D DL outperforms both 2D and 3D DL in terms of noise reduction. We also compare the computational costs, and 2.5D DL shows strong advantage over 3D DL in both full-view and sparse-view cases.

  13. Chemical PM2.5 Speciation in Major Cities Worldwide

    NASA Astrophysics Data System (ADS)

    Snider, Graydon; Weagle, Crystal; Brauer, Michael; Cohen, Aaron; Gibson, Mark; Liu, Yang; Martins, Vanderlei; Rudich, Yinon; Martin, Randall

    2016-04-01

    We examined the chemical composition of fine particulate matter (PM2.5) across 13 globally dispersed urban locations (including Atlanta, Buenos Aires, Beijing, Manila, and Dhaka), as part of the Surface PARTiculate mAtter Network (SPARTAN). At each site sampling was conducted over 4 to 24 months for the years 2013 to 2015. Analysis of filter samples revealed that several PM2.5 chemical components varied by more than an order of magnitude between sites. Ammonium sulfate ranged from 2 μg m-3 (Ilorin) to 17 μg m-3 (Kanpur). Ammonium nitrate ranged from 0.2 μg m-3 (Atlanta) to 6.7 μg m-3 (Kanpur). Effective black carbon ranged from 0.4 μg m-3 (Atlanta) to 5 μg m-3 (Dhaka and Kanpur). The all-site mean values of major PM2.5 constituents were ammonium sulfate (20 ± 10 %), crustal material (12 ± 6.5%), effective black carbon (10 ± 7.4 %), ammonium nitrate (3.7 ± 2.5%), sea salt (2.2 ± 1.5%), trace element oxides (0.9 ± 0.7 %), water (7.2 ± 3.0%) and residue materials (44 ± 24%). Based on the evaluation with collocated studies we treated residue material as mostly organic. Major ions generally agreed well with previous studies at the same urban locations (e.g. sulfate fractions agreed within 4% for eight out of 11 collocation comparisons). Enhanced crustal material (CM) concentrations with high Zn:Al ratios at large cities (e.g. Hanoi, Dhaka, Manila) imply significant anthropogenic CM contributions that deserve more attention. Detailed chemical speciation also aided our characterization of site-specific PM2.5 water retention. The expected water contribution to aerosols was calculated via the hygroscopicity parameter for each filter. Hourly PM2.5 at specified relative humidity (35%) was inferred from nephelometer measurements of light scatter at ambient relative humidity and 9-day filter measurements of PM2.5 mass. Our PM2.5 estimates compared favorably with a beta attenuation monitor (BAM) at the nearby US embassy in Beijing, with a coefficient of variation

  14. Effect of estrogen administration on rat liver 2-5A synthetase activity.

    PubMed

    Smekens, M; Dumont, J E; Degeyter, A; Galand, P

    1986-08-01

    Interferon-induced 2-5A synthetase is also present in various cells and tissues in the absence of any interferon treatment. The activity of this enzyme, which synthesizes a series of oligoadenylates, ppp(A2'p)n5'A (collectively referred to as 2-5A), was previously shown to vary with the growth status of liver tissue i.e., it decreased before and during the peak of DNA synthesis activity induced in rat liver by a two third hepatectomy. In the course of studies aimed at testing the hypothesis that 2-5A synthetase activity might exert negative control on normal cell growth and multiplication, we show here that a treatment of ovariectomized rats with a single dose of estradiol-17beta (100 micrograms/100 g body weight) induced a transient increase in the [3H]thymidine labelling index in the liver after 24 h and markedly decreased the 2-5A synthetase activity. A time course study revealed that 2-5A synthetase activity started to decrease after 3 h, reaching a minimal value (10% of the control level) after 12 h, then slowly increased to come back to control level at 48 h. These results, together with our similar data on regenerating liver, suggest that low 2-5A synthetase activity is permissive for acquisition of proliferative 'competence' by G0 cells. PMID:3730433

  15. Portable Life Support System 2.5 Fan Design and Development

    NASA Technical Reports Server (NTRS)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2016-01-01

    NASA is building a high-fidelity prototype of an advanced Portable Life Support System (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, was driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement were identified with the PLSS 2.0 fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0, and it uses the same nonmetallic, canned motor, with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 ventilation loop. The larger impeller allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds consistent with prior, oxygen-rated fans. Development of the fan also considered a shrouded impeller design that could allow larger clearances for greater oxygen safety, assembly tolerances and particle ingestion. This paper discusses the design, manufacturing and performance testing of the new fans.

  16. PM 2.5 Airborne Particulates Near Frac Sand Operations.

    PubMed

    Walters, Kristin; Jacobson, Jeron; Kroening, Zachary; Pierce, Crispin

    2015-11-01

    The rapid growth of hydraulic fracturing for oil and gas extraction in the U.S. has led to 135 active "frac" sand mines, processing plants, and rail transfer stations in Wisconsin. Potential environmental health risks include increased truck traffic, noise, ecosystem loss, and groundwater, light, and air pollution. Emitted air contaminants include fine particulate matter (PM2.5) and respirable crystalline silica. Inhalation of fine dust particles causes increased mortality, cardiovascular disease, lung disease, and lung cancer. In the authors' pilot study, use of a filter-based ambient particulate monitor found PM2.5 levels of 5.82-50.8 µg/m3 in six 24-hour samples around frac sand mines and processing sites. Enforcement of the existing U.S. Environmental Protection Agency annual PM2.5 standard of 12 µg/m3 is likely to protect the public from silica exposure risks as well. PM2.5 monitoring around frac sand sites is needed to ensure regulatory compliance, inform nearby communities, and protect public health.

  17. 43 CFR 3472.2-5 - Special qualifications, public bodies.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Special qualifications, public bodies... PROVISIONS AND LIMITATIONS Lease Qualification Requirements § 3472.2-5 Special qualifications, public bodies... public body shall submit: (1) Evidence of the manner in which it is organized; (2) Evidence that it...

  18. Source apportionment of PM2.5 in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.-B.; Hopke, P. K.; Yi, S.-M.

    2009-07-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using positive matrix factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 source categories were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major contributors of PM2.5 were secondary nitrate (20.9%), secondary sulfate (20.5%), gasoline-fueled vehicles (17.2%), and biomass burning (12.1%), with lesser contributions from diesel emissions (8.1%), soil (7.4%), industry (6.7%), road salt and two-stroke vehicles (5.1%), and aged sea salt (2.2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional probability function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential source contribution function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.

  19. Source apportionment of PM2.5 in Seoul, Korea

    NASA Astrophysics Data System (ADS)

    Heo, J.-B.; Hopke, P. K.; Yi, S.-M.

    2008-12-01

    PM2.5 samples were collected at a centrally located urban monitoring site in Seoul, Korea, every third day from March 2003 to December 2006 and analyzed for their chemical constituents. Sources were identified using Positive Matrix Factorization (PMF). A total of 393 samples were obtained during the sampling period, and 20 chemical species were measured. Nine PM2.5 sources were identified providing physically realistic profiles and interesting insights into the source contributions to the ambient mass concentrations. The major sources of PM2.5 were secondary nitrate (20%), secondary sulfate (20%), gasoline-fueled vehicles (17%), and biomass burning (12%), with lesser contributions from diesel emissions (8%), soil (7%), industry (6%), road salt and two-stroke engine (5%), and aged sea salt (2%). PM2.5 levels in Seoul were influenced by both local urban activities and regional-scale transport. Conditional Probability Function (CPF) results identified possible source directions of local sources such as motor vehicles (gasoline and diesel), industry, and road salt. Potential Source Contribution Function (PSCF) results showed that possible source areas contributing to the elevated secondary particle concentrations (sulfate and nitrate) in Seoul to be the major industrial areas in China.

  20. Science in Action Series: AGATE (pt 2/5 )

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This show was made for the Office of Education at NASA Langley. The objective is to make math and science appealing to a middle school audience. This clip (pt 2/5 ) is an animation which tells us a little about the plane itself: including capacity, speed and range.

  1. 2,5-hexanedione-induced immunomodulatory effect in mice

    SciTech Connect

    Upreti, R.K.; Shanker, R.

    1987-06-01

    The immunotoxic potential of 2,5-hexanedione (2,5-Hxdn), the end metabolite of n-hexane/methyl n-butyl ketone, was evaluated in a mouse model involving multiple pathomorphological, hematological, and immunological assays. Young adult male Swiss albino mice were given either single or seven consecutive oral doses of 0.2 x LD/sub 50/ of 2.5-Hxdn. None of the treated mice exhibited any sign of hind limb weakness up to 1 week. On the eighth day, half the animals were sacrificed for initial pathomorphological studies of various organs and the other half were subjected to several immune function tests. The results revealed treatment-related reduction in cellularity of spleen, thymus, and mesentric lymph nodes and pathotoxicological changes. Further, immune function tests such as delayed-type hypersensitivity reaction, plaque-forming cell assay, phagocytosis by adherent peritoneal exudate cells, and resistance to endotoxin shock were considerably impaired. These results suggest that 2,5-Hxdn treatment causes profound impairment of immunity in mice even before the onset of peripheral neuropathy.

  2. PM 2.5 Airborne Particulates Near Frac Sand Operations.

    PubMed

    Walters, Kristin; Jacobson, Jeron; Kroening, Zachary; Pierce, Crispin

    2015-11-01

    The rapid growth of hydraulic fracturing for oil and gas extraction in the U.S. has led to 135 active "frac" sand mines, processing plants, and rail transfer stations in Wisconsin. Potential environmental health risks include increased truck traffic, noise, ecosystem loss, and groundwater, light, and air pollution. Emitted air contaminants include fine particulate matter (PM2.5) and respirable crystalline silica. Inhalation of fine dust particles causes increased mortality, cardiovascular disease, lung disease, and lung cancer. In the authors' pilot study, use of a filter-based ambient particulate monitor found PM2.5 levels of 5.82-50.8 µg/m3 in six 24-hour samples around frac sand mines and processing sites. Enforcement of the existing U.S. Environmental Protection Agency annual PM2.5 standard of 12 µg/m3 is likely to protect the public from silica exposure risks as well. PM2.5 monitoring around frac sand sites is needed to ensure regulatory compliance, inform nearby communities, and protect public health. PMID:26638669

  3. 11 CFR 2.5 - Procedures for closing meetings.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... attached to, and preserved with, the statement required by 11 CFR 2.5(d). (c) Voting procedures. (1) No... each item on an agenda proposed to be closed in whole or in part pursuant to 11 CFR 2.4, or with respect to any information proposed to be withheld under 11 CFR 2.4. (ii) A single vote may be taken...

  4. 11 CFR 2.5 - Procedures for closing meetings.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... attached to, and preserved with, the statement required by 11 CFR 2.5(d). (c) Voting procedures. (1) No... each item on an agenda proposed to be closed in whole or in part pursuant to 11 CFR 2.4, or with respect to any information proposed to be withheld under 11 CFR 2.4. (ii) A single vote may be taken...

  5. 11 CFR 2.5 - Procedures for closing meetings.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... attached to, and preserved with, the statement required by 11 CFR 2.5(d). (c) Voting procedures. (1) No... each item on an agenda proposed to be closed in whole or in part pursuant to 11 CFR 2.4, or with respect to any information proposed to be withheld under 11 CFR 2.4. (ii) A single vote may be taken...

  6. 11 CFR 2.5 - Procedures for closing meetings.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... attached to, and preserved with, the statement required by 11 CFR 2.5(d). (c) Voting procedures. (1) No... each item on an agenda proposed to be closed in whole or in part pursuant to 11 CFR 2.4, or with respect to any information proposed to be withheld under 11 CFR 2.4. (ii) A single vote may be taken...

  7. Extending Interactive Writing into Grades 2-5

    ERIC Educational Resources Information Center

    Roth, Kate; Dabrowski, Joan

    2014-01-01

    Interactive writing is an instructional practice widely considered effective and most appropriate for emergent writers. This article asserts that it is a valuable method for more fluent writers in grades 2-5. It outlines the basic lesson sequence and proposes four key shifts to adapt interactive writing for older, more fluent writers: 1) The…

  8. 75 FR 14259 - Transportation Conformity Rule PM2.5

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-24

    .... EPA first promulgated the transportation conformity rule on November 24, 1993 (58 FR 62188), and... a final rule EPA published on July 1, 2004 (69 FR 40004), EPA provided conformity procedures for... Precursors'' (70 FR 24280). This final rule specified transportation-related PM 2.5 precursors and when...

  9. Correlation between microstructure and charge transport in poly(2,5-dimethoxy- p -phenylenevinylene) thin films

    NASA Astrophysics Data System (ADS)

    Sims, M.; Tuladhar, S. M.; Nelson, J.; Maher, R. C.; Campoy-Quiles, M.; Choulis, S. A.; Mairy, M.; Bradley, D. D. C.; Etchegoin, P. G.; Tregidgo, C.; Suhling, K.; Richards, D. R.; Massiot, P.; Nielsen, C. B.; Steinke, J. H. G.

    2007-11-01

    We report a study of thin films of poly(2,5-dimethoxy- p -phenylenevinylene) (PDMeOPV) prepared by a precursor route. Conversion at two different temperatures, namely, 120 and 185°C , produces partially and fully converted films. We study the structural, optical, and charge transport characteristics of these samples in order to relate transport properties to microstructure. Micro-Raman mapping and photoluminescence (PL) imaging reveal the existence of coarse, depth-averaged domains of around 50μm in lateral extent, with more pronounced contrast for conversion at the higher temperature. The contrast in both micro-Raman and PL maps can be attributed to fluctuations in film density. Spectroscopic ellipsometry studies of the films indicate that the average film density is approximately 15% higher for conversion at the higher temperature. Time-of-flight photocurrent transients, recorded here in PDMeOPV films, are typically dispersive but yield hole mobilities in excess of 10-4cm2/Vs at modest applied fields (˜1.2×105V/cm) in the fully converted films. To our knowledge, these are amongst the highest reported mobility values for a poly( p -phenylenevinylene) derivative. Fully converted films, while yielding higher hole mobilities, exhibit a stronger dependence on electric field than partially converted ones. The higher mobility can be attributed to the almost complete conversion of the flexible saturated subunits within precursor chains to conjugated vinylene moieties at elevated temperature. This results in a correspondingly higher packing density, an improvement in intrachain transport, and a reduction in the smallest interchain hopping distance. We suggest that the stronger electric field dependence is due to the increasing influence of intermolecular electrostatic interactions with decreasing interchain separation. We propose that a greater proportion of chains in the fully converted films packs in a three-dimensional, interdigitated arrangement similar to that

  10. Job-Sharing at the Greater Victoria Public Library.

    ERIC Educational Resources Information Center

    Miller, Don

    1978-01-01

    Describes the problems associated with the management of part-time library employees and some solutions afforded by a job sharing arrangement in use at the Greater Victoria Public Library. This is a voluntary work arrangement, changing formerly full-time positions into multiple part-time positions. (JVP)

  11. Design and signal processing of a sector SSPA for PM2.5 monitoring

    NASA Astrophysics Data System (ADS)

    Wu, Kaihua; Ma, Li; Guo, Miao; Jiang, Peng

    2008-03-01

    PM2.5 is the chief air pollutants in most Chinese City. The PM2.5 parameter was usually evaluated by the weight per unit volume (mg/m 3) and the size was generally ignored. A method measuring the particle size distribution of PM2.5 based on light scattering was put forward. A special sector sensor, SSPA(Self Scanning Photodiode Array), was designed to detect the distribution of weak space light energy. We researched a special optoelectronic detector with sector detection area. The sensor has high sensitivity and high reliability. It's suitable for detecting the distribution of space light energy, especially the diffraction and scattering energy distribution. The paper researched the signal processing method. Based on the principle and characteristics of SSPA, a signal acquisition and processing method controlled by computer was introduced. The amplification of weak signal, the matching of time sequence, the fast peak holding with low leakage, the high speed A/D conversion and nonlinear correction were discussed. The method can acquire the peak signal of every ring of sector SSPA with high accuracy and in real time. The particle size distribution of PM2.5 acquired in Hangzhou City was analyzed. Results showed that the particles with diameter below 2.5um were above 90%.

  12. Chemical Characterization of Outdoor and Subway Fine (PM2.5–1.0) and Coarse (PM10–2.5) Particulate Matter in Seoul (Korea) by Computer-Controlled Scanning Electron Microscopy (CCSEM)

    PubMed Central

    Byeon, Sang-Hoon; Willis, Robert; Peters, Thomas M.

    2015-01-01

    Outdoor and indoor (subway) samples were collected by passive sampling in urban Seoul (Korea) and analyzed with computer-controlled scanning electron microscopy coupled with energy dispersive x-ray spectroscopy (CCSEM-EDX). Soil/road dust particles accounted for 42%–60% (by weight) of fine particulate matter larger than 1 µm (PM2.5–1.0) in outdoor samples and 18% of PM2.5–1.0 in subway samples. Iron-containing particles accounted for only 3%–6% in outdoor samples but 69% in subway samples. Qualitatively similar results were found for coarse particulate matter (PM10–2.5) with soil/road dust particles dominating outdoor samples (66%–83%) and iron-containing particles contributing most to subway PM10–2.5 (44%). As expected, soil/road dust particles comprised a greater mass fraction of PM10–2.5 than PM2.5–1.0. Also as expected, the mass fraction of iron-containing particles was substantially less in PM10–2.5 than in PM2.5–1.0. Results of this study are consistent with known emission sources in the area and with previous studies, which showed high concentrations of iron-containing particles in the subway compared to outdoor sites. Thus, passive sampling with CCSEM-EDX offers an inexpensive means to assess PM2.5–1.0 and PM10-2.5 simultaneously and by composition at multiple locations. PMID:25689348

  13. DEVELOPMENT AND EVALUATION OF A CONTINUOUS COARSE (PM10-PM2.5) PARTICLE MONITOR

    EPA Science Inventory

    In this paper, we describe the development and laboratory and field evaluation of a continuous coarse (2.5-10 um) particle mass (PM) monitor that can provide reliable measurements of the coarse mass (CM) concentrations in time intervals as short as 5-10 min. The operating princ...

  14. Genotoxicity biomarkers for airborne particulate matter (PM2.5) in an area under petrochemical influence.

    PubMed

    Lemos, Andréia Torres; Lemos, Clarice Torres de; Flores, Andressa Negreiros; Pantoja, Eduarda Ozório; Rocha, Jocelita Aparecida Vaz; Vargas, Vera Maria Ferrão

    2016-09-01

    The effects of fine inhalable particles (PM2.5) were evaluated in an area under the influence of a petrochemical industry, investigating the sensitivity of different genotoxicity biomarkers. Organic extracts were obtained from PM2.5 samples at two sites, positioned in the first and second preferential wind direction in the area. The extracts were evaluated with Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024. The mammalian metabolization fraction (S9) was used to evaluate metabolite mutagenicity. The Comet Assay (CA) and Micronuclei Test were used in a Chinese hamster lung cell line (V79). All extracts showed mutagenicity in Salmonella, and nitrogenated compounds were strongly present. Genotoxicity were found in CA in almost all extracts and the micronuclei induction at the Site in the first (Autumn 1, Winter 1), and in the second (Spring 2) wind direction. V79 showed cytotoxicity in all samples. The three biomarkers were concordant in characterization Site NO with worse quality, compatible with the greater pollutants dispersion in the first wind direction. All PM2.5 concentrations were lower than those recommended by air quality standards but genotoxic effects were detected in all samples, corroborating that these standards are inadequate as quality indicators. The Salmonella/microsome assay proved sensitive to PM2.5 mutagenicity, with an outstanding influence of nitroarenes and aromatic amines. Analyses using CA and the micronucleus test broadened the levels of response that involve different damage induction mechanisms. Results show that the complex PM2.5 composition can provoke various genotoxic effects and the use of different bioassays is essential to understand its effects.

  15. Genotoxicity biomarkers for airborne particulate matter (PM2.5) in an area under petrochemical influence.

    PubMed

    Lemos, Andréia Torres; Lemos, Clarice Torres de; Flores, Andressa Negreiros; Pantoja, Eduarda Ozório; Rocha, Jocelita Aparecida Vaz; Vargas, Vera Maria Ferrão

    2016-09-01

    The effects of fine inhalable particles (PM2.5) were evaluated in an area under the influence of a petrochemical industry, investigating the sensitivity of different genotoxicity biomarkers. Organic extracts were obtained from PM2.5 samples at two sites, positioned in the first and second preferential wind direction in the area. The extracts were evaluated with Salmonella/microsome assay, microsuspension method, strains TA98, YG1021 and YG1024. The mammalian metabolization fraction (S9) was used to evaluate metabolite mutagenicity. The Comet Assay (CA) and Micronuclei Test were used in a Chinese hamster lung cell line (V79). All extracts showed mutagenicity in Salmonella, and nitrogenated compounds were strongly present. Genotoxicity were found in CA in almost all extracts and the micronuclei induction at the Site in the first (Autumn 1, Winter 1), and in the second (Spring 2) wind direction. V79 showed cytotoxicity in all samples. The three biomarkers were concordant in characterization Site NO with worse quality, compatible with the greater pollutants dispersion in the first wind direction. All PM2.5 concentrations were lower than those recommended by air quality standards but genotoxic effects were detected in all samples, corroborating that these standards are inadequate as quality indicators. The Salmonella/microsome assay proved sensitive to PM2.5 mutagenicity, with an outstanding influence of nitroarenes and aromatic amines. Analyses using CA and the micronucleus test broadened the levels of response that involve different damage induction mechanisms. Results show that the complex PM2.5 composition can provoke various genotoxic effects and the use of different bioassays is essential to understand its effects. PMID:27343868

  16. PLSS 2.5 Fan Design and Development

    NASA Technical Reports Server (NTRS)

    Quinn, Gregory; Carra, Michael; Converse, David; Chullen, Cinda

    2015-01-01

    NASA is building a high fidelity prototype of an advanced portable life support system (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge in order to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement have been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5.

  17. Ambiphilic boron in 1,4,2,5-diazadiborinine.

    PubMed

    Wang, Baolin; Li, Yongxin; Ganguly, Rakesh; Hirao, Hajime; Kinjo, Rei

    2016-01-01

    Boranes have long been known as the archetypal Lewis acids owing to an empty p-orbital on the boron centre. Meanwhile, Lewis basic tricoordinate boranes have been developed in recent years. Here we report the synthesis of an annulated 1,4,2,5-diazadiborinine derivative featuring boron atoms that exhibit both Lewis acidic and basic properties. Experimental and computational studies confirmed that two boron atoms in this molecule are spectroscopically equivalent. Nevertheless, this molecule cleaves C-O, B-H, Si-H and P-H bonds heterolytically, and readily undergoes [4+2] cycloaddition reaction with non-activated unsaturated bonds such as C=O, C=C, C≡C and C≡N bonds. The result, thus, indicates that the indistinguishable boron atoms in 1,4,2,5-diazadiborinine act as both nucleophilic and electrophilic centres, demonstrating ambiphilic nature. PMID:27279265

  18. Ambiphilic boron in 1,4,2,5-diazadiborinine

    PubMed Central

    Wang, Baolin; Li, Yongxin; Ganguly, Rakesh; Hirao, Hajime; Kinjo, Rei

    2016-01-01

    Boranes have long been known as the archetypal Lewis acids owing to an empty p-orbital on the boron centre. Meanwhile, Lewis basic tricoordinate boranes have been developed in recent years. Here we report the synthesis of an annulated 1,4,2,5-diazadiborinine derivative featuring boron atoms that exhibit both Lewis acidic and basic properties. Experimental and computational studies confirmed that two boron atoms in this molecule are spectroscopically equivalent. Nevertheless, this molecule cleaves C–O, B–H, Si–H and P–H bonds heterolytically, and readily undergoes [4+2] cycloaddition reaction with non-activated unsaturated bonds such as C=O, C=C, C≡C and C≡N bonds. The result, thus, indicates that the indistinguishable boron atoms in 1,4,2,5-diazadiborinine act as both nucleophilic and electrophilic centres, demonstrating ambiphilic nature. PMID:27279265

  19. Comprehensive characterization of PM2.5 aerosols in Singapore

    NASA Astrophysics Data System (ADS)

    Balasubramanian, R.; Qian, W.-B.; Decesari, S.; Facchini, M. C.; Fuzzi, S.

    2003-08-01

    A comprehensive characterization of PM2.5 aerosols collected in Singapore from January through December 2000 is presented. The annual average mass concentration of PM2.5 was 27.2 μg/m3. The atmospheric loading of PM2.5 was elevated sporadically from March through May, mainly due to advection of biomass burning (deliberate fires to clear plantation areas) impacted air masses from Sumatra, Indonesia. Satellite images of the area, trajectory calculations, and surface wind direction data are in support of the transport of pyrogenic products from Sumatra toward Singapore. Aerosol samples collected during the dry season were analyzed for water-soluble ions, water-soluble organic compounds (WSOC), elemental carbon (EC), organic carbon, and trace elements using a number of analytical techniques. The major components were sulfate, EC, water-soluble carbonaceous materials, and water-insoluble carbonaceous materials. Aerosol WSOC were characterized based on a combination of chromatographic separations by ion exchange chromatography, functional group investigation by proton nuclear magnetic resonance, and total organic carbon determination. The comprehensive chemical characterization of PM2.5 particles revealed that both non-sea-salt sufate (nss-SO42-) and carbonaceous aerosols mainly contributed to the increase in the mass concentration of aerosols during the smoke haze period. Using a mass closure test (a mass balance), we determined whether the physical measurement of gravimetric fine PM concentration of a sample is equal to the summed concentrations of the individually identified chemical constituents (measured or inferred) in the sample. The sum of the determined groups of aerosol components and the gravimetrically determined mass agreed reasonably well. Principal component analysis was performed from the combined data set, and five factors were observed: a soil dust component, a metallurgical industry factor, a factor representing emissions from biomass burning and

  20. /sup 125/I)-(d(CH2)5, Sar7)AVP: a selective radioligand for V1 vasopressin receptors

    SciTech Connect

    Kelly, J.M.; Abrahams, J.M.; Phillips, P.A.; Mendelsohn, F.A.; Grzonka, Z.; Johnston, C.I.

    1989-01-01

    Arginine8-vasopressin (AVP) acts on vascular and hepatic V1 receptors to influence blood pressure and glycogenolysis respectively. We have radioiodinated the AVP V1 receptor antagonist, (1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic-acid), 7-sarcosine, 8-arginine) vasopressin ((d(CH2)5, Sar7)AVP) and determined its receptor-binding properties in rat liver and kidney plasma membranes. The binding was of high affinity to single classes of receptors (liver: Kd = 3.0 nM and Bmax = 530 +/- 10 fmol/mg protein, kidney: Kd = 0.5 +/- 0.9 nM and Bmax = 11 +/- 8 fmol/mg protein). Competition of (125I)-(d(CH2)5, Sar7)AVP binding by unlabelled AVP analogues gave the following order of potency in both tissues, consistent with that expected for binding to a V1 receptor: (d(CH2)5, Tyr(Me)2)AVP greater than AVP greater than (d(CH2)5, D-Ile2, Ile4) AVP greater than DDAVP. No degradation of (125I)-(d(CH2)5, Sar7)AVP during incubation or storage was detected by HPLC analysis. We have used (125I)-(d(CH2)5, Sar7)AVP and in vitro autoradiography to demonstrate its use in localizing brain AVP receptors. These studies suggest that (125I)-(d(CH2)5, Sar7)AVP is a suitable selective radioligand for labelling V1 receptors and will provide a valuable tool for the study of the localization and regulation of AVP V1 receptors in tissues and in receptor isolation.

  1. Air Pollution Exposure Model for Individuals (EMI) in Health Studies: Evaluation for Ambient PM2.5

    EPA Science Inventory

    Health studies of fine particulate matter (PM2.5) often use outdoor concentrations as exposure surrogates, which fail to account for indoor attenuation of ambient PM2.5 and time indoors. To address these limitations, we developed an air pollution exposure model for individuals (E...

  2. The concentrations and sources of PM 2.5 in metropolitan New York City

    NASA Astrophysics Data System (ADS)

    Qin, Youjun; Kim, Eugene; Hopke, Philip K.

    The concentration time series of chemical species measured in PM 2.5 samples from four speciation trend network (STN) sites in the New York City metropolitan area and a upwind background site were explored. PM 2.5 concentrations and chemical compositions measured in metropolitan area of New York City are uniform. About 69-82% of PM 2.5 mass derives from transport. The most important constituents of the PM 2.5 were SO42-, NH 4 and NO3- and account 54-67% of PM 2.5 mass. More than 93% of SO42- and about 54-65% of NO3- are likely to have been transported into the NYC area based on the concentrations observed at the background site. Backward air parcel trajectories indicate that coal-fired power plants in the border area among West Virginia, Ohio and Pennsylvania are related to typical high PM 2.5 events having peak secondary pollutant concentrations in New York City. Positive matrix factorization (PMF) was applied to identify the PM 2.5 sources and estimate the source contributions. Sources common to all five sites included secondary sulfate, secondary nitrate, soil and aged sea salt. Oil combustion was identified at four of the sites. At the Elizabeth site, the oil combustion source appears to show an influence from ship emissions. Motor vehicles were apportioned into two sources (gasoline and diesel) at three site and three sources at the Elizabeth site, probably because of its proximity to a major interstate highway. At the Queens College site, only a combined motor vehicle factor could be resolved. The source profiles, source contributions and seasonal or weekday variations derived by PMF are compared to source inventories for the area. It appears that there were more vehicle exhausts and less dust and wood smoke than are indicated by the source inventories.

  3. PM2.5 constituents and oxidative DNA damage in humans.

    PubMed

    Wei, Yongjie; Han, In-Kyu; Shao, Min; Hu, Min; Zhang, O Junfeng; Tang, Xiaoyan

    2009-07-01

    Previous studies suggested that certain constituents of ambient PM2.5 can induce or increase oxidative stress in biological systems. The present study is designed to examine whether exposure to traffic generated particles increases the burden of oxidative stress in humans and to identify specific PM2.5 constituents responsible for pollution-induced oxidative stress. We recruited two nonsmoking security guards who worked at a university campus gate by a heavily trafficked road. Pre- and post-workshift spot urines were collected on each of the 29 days of measurement. Concentrations of PM2.5 mass and 126 chemical species were measured at the worksite and a campus background site simultaneously. Urine samples were analyzed for 8-hydroxy-2'-deoxyguanosine (8-OHdG). Factor analysis and linear mixed-effects regression models were used in statistical analyses. Three clusters of PM2.5 species were identified, including PAHs, metals, and polar organic compounds. Urinary concentrations of 8-OHdG increased by > 3 times following an eight-hour workshift in participants. Pre-workshift urinary concentrations of 8-OHdG were associated with PM2.5 concentrations at the background site. Post-workshift 8-OHdG concentrations were significantly and positively associated with PM2.5 mass, PAHs, and metals, but not polar organic species, measured at the worksite. Our findings provide direct evidence in humans that PM compositions are important in increasing oxidative stress burdens. Our results support that PAHs and metals are biologically active constituents of PM2.5 with regards to the induction of oxidative DNA damages in the human body. PMID:19673262

  4. 2.5D Cartoon Hair Modeling and Manipulation.

    PubMed

    Yeh, Chih-Kuo; Jayaraman, Pradeep Kumar; Liu, Xiaopei; Fu, Chi-Wing; Lee, Tong-Yee

    2015-03-01

    This paper addresses a challenging single-view modeling and animation problem with cartoon images. Our goal is to model the hairs in a given cartoon image with consistent layering and occlusion, so that we can produce various visual effects from just a single image. We propose a novel 2.5D modeling approach to deal with this problem. Given an input image, we first segment the hairs of the cartoon character into regions of hair strands. Then, we apply our novel layering metric, which is derived from the Gestalt psychology, to automatically optimize the depth ordering among the hair strands. After that, we employ our hair completion method to fill the occluded part of each hair strand, and create a 2.5D model of the cartoon hair. By using this model, we can produce various visual effects, e.g., we develop a simplified fluid simulation model to produce wind blowing animations with the 2.5D hairs. To further demonstrate the applicability and versatility of our method, we compare our results with real cartoon hair animations, and also apply our model to produce a wide variety of hair manipulation effects, including hair editing and hair braiding. PMID:26357063

  5. A green approach towards adoption of chemical reaction model on 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane decomposition by differential isoconversional kinetic analysis.

    PubMed

    Das, Mitali; Shu, Chi-Min

    2016-01-15

    This study investigated the thermal degradation products of 2,5-dimethyl-2,5-di-(tert-butylperoxy) hexane (DBPH), by TG/GC/MS to identify runaway reaction and thermal safety parameters. It also included the determination of time to maximum rate under adiabatic conditions (TMR(ad)) and self-accelerating decomposition temperature obtained through Advanced Kinetics and Technology Solutions. The apparent activation energy (Ea) was calculated from differential isoconversional kinetic analysis method using differential scanning calorimetry experiments. The Ea value obtained by Friedman analysis is in the range of 118.0-149.0 kJ mol(-1). The TMR(ad) was 24.0 h with an apparent onset temperature of 82.4°C. This study has also established an efficient benchmark for a thermal hazard assessment of DBPH that can be applied to assure safer storage conditions.

  6. Greater trochanteric pain syndrome diagnosis and treatment.

    PubMed

    Mallow, Michael; Nazarian, Levon N

    2014-05-01

    Lateral hip pain, or greater trochanteric pain syndrome, is a commonly seen condition; in this article, the relevant anatomy, epidemiology, and evaluation strategies of greater trochanteric pain syndrome are reviewed. Specific attention is focused on imaging of this syndrome and treatment techniques, including ultrasound-guided interventions. PMID:24787333

  7. Greater trochanteric pain syndrome diagnosis and treatment.

    PubMed

    Mallow, Michael; Nazarian, Levon N

    2014-05-01

    Lateral hip pain, or greater trochanteric pain syndrome, is a commonly seen condition; in this article, the relevant anatomy, epidemiology, and evaluation strategies of greater trochanteric pain syndrome are reviewed. Specific attention is focused on imaging of this syndrome and treatment techniques, including ultrasound-guided interventions.

  8. [Estimation of PM2.5 Concentration over the Yangtze Delta Using Remote Sensing: Analysis of Spatial and Temporal Variations].

    PubMed

    Xu, Jian-hui; Jiang, Hong

    2015-09-01

    Satellite remote sensing retrieved aerosol optical thickness is widely used to monitor surface PM2.5 concentration. In order to monitor PM2.5 by remote sensing in the Yangtze delta, estimate model of PM2.5 concentration was constructed based on MODIS AOT, PM2.5 concentration data of the 36 ground air quality observation sites and meteorological data in 2013. Afterwards, the model estimated PM2.5 was validated by PM2.5 concentration data from the 17 ground air quality observation sites, and the results showed that the model estimation was higher. The correlation coefficient value of R2 between model estimation of PM2.5 concentration and the value of the ground monitoring of spring, summer, autumn and winter were 0. 45, 0. 50, 0. 58 and 0. 52, respectively. The variation characteristics of temporal and spatial was analyzed based on the long time PM2.5 data together with model estimated, and an increase trend of PM2.5 concentration was observed from 2000 to 2013, with the maximum concentration of PM2.5 (66. 2 µg.m-3 ± 19. 3 µg.m-3) in February and minimum in December (22.6 µg.m-3 ± 5. 9 µg.m-3). In addition, it was found that the distribution of PM2.5 concentration was of obvious features, displaying high value in south and low in north. Mass concentration of PM2.5 was peaked in the zone of urban agglomeration which was grouped to a delta-shaped region by Shanghai, Hangzhou and Nanjing, while the low value areas were in the forest away from city. The result suggested that MODIS AOT and meteorological data can be used to monitor regional PM2.5 by the established multi-linear regression model.

  9. [Estimation of PM2.5 Concentration over the Yangtze Delta Using Remote Sensing: Analysis of Spatial and Temporal Variations].

    PubMed

    Xu, Jian-hui; Jiang, Hong

    2015-09-01

    Satellite remote sensing retrieved aerosol optical thickness is widely used to monitor surface PM2.5 concentration. In order to monitor PM2.5 by remote sensing in the Yangtze delta, estimate model of PM2.5 concentration was constructed based on MODIS AOT, PM2.5 concentration data of the 36 ground air quality observation sites and meteorological data in 2013. Afterwards, the model estimated PM2.5 was validated by PM2.5 concentration data from the 17 ground air quality observation sites, and the results showed that the model estimation was higher. The correlation coefficient value of R2 between model estimation of PM2.5 concentration and the value of the ground monitoring of spring, summer, autumn and winter were 0. 45, 0. 50, 0. 58 and 0. 52, respectively. The variation characteristics of temporal and spatial was analyzed based on the long time PM2.5 data together with model estimated, and an increase trend of PM2.5 concentration was observed from 2000 to 2013, with the maximum concentration of PM2.5 (66. 2 µg.m-3 ± 19. 3 µg.m-3) in February and minimum in December (22.6 µg.m-3 ± 5. 9 µg.m-3). In addition, it was found that the distribution of PM2.5 concentration was of obvious features, displaying high value in south and low in north. Mass concentration of PM2.5 was peaked in the zone of urban agglomeration which was grouped to a delta-shaped region by Shanghai, Hangzhou and Nanjing, while the low value areas were in the forest away from city. The result suggested that MODIS AOT and meteorological data can be used to monitor regional PM2.5 by the established multi-linear regression model. PMID:26717669

  10. Heterogeneous 2.5D integration on through silicon interposer

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaowu; Lin, Jong Kai; Wickramanayaka, Sunil; Zhang, Songbai; Weerasekera, Roshan; Dutta, Rahul; Chang, Ka Fai; Chui, King-Jien; Li, Hong Yu; Wee Ho, David Soon; Ding, Liang; Katti, Guruprasad; Bhattacharya, Suryanarayana; Kwong, Dim-Lee

    2015-06-01

    Driven by the need to reduce the power consumption of mobile devices, and servers/data centers, and yet continue to deliver improved performance and experience by the end consumer of digital data, the semiconductor industry is looking for new technologies for manufacturing integrated circuits (ICs). In this quest, power consumed in transferring data over copper interconnects is a sizeable portion that needs to be addressed now and continuing over the next few decades. 2.5D Through-Si-Interposer (TSI) is a strong candidate to deliver improved performance while consuming lower power than in previous generations of servers/data centers and mobile devices. These low-power/high-performance advantages are realized through achievement of high interconnect densities on the TSI (higher than ever seen on Printed Circuit Boards (PCBs) or organic substrates), and enabling heterogeneous integration on the TSI platform where individual ICs are assembled at close proximity (<1 mm separation) compared with several centimeters on a typical PCB. In this paper, we have outlined the benefits of adopting 2.5D TSI technology and also highlighted the current day approaches to implement this technology in Si fabrication facilities, and in assembly/packaging factories. While the systems and devices that power the mobile society benefit from exploiting advantages of 2.5D integration on TSI, there do exist surmountable challenges that need to be addressed for this relatively new technology to be used in high volume production of next generation semiconductor devices. The key areas of focus and challenges include: Technology planning and design-execution that are necessary for harnessing 2.5D TSI for building systems, processing flow for the fabrication of 100 μm thick TSI at acceptable costs, manufacturing flow for assembling multiple ICs on a 100 μm thick TSI in a repeatable, and reliable manner, thermo-mechanical analysis and optimization for addressing warpage issues, and thermal

  11. Trifluoroacetic Acid Level in the Atmosphere of Beijing and Its Relationship with PM2.5

    NASA Astrophysics Data System (ADS)

    Guo, Junyu; Zhang, Jianbo

    2016-04-01

    Atmospheric concentrations of Trifluoroacetic Acid (TFA), one of the main degradation products of HCFC-123, HCFC-124 and HFC-134a, were detected in Beijing, China between 2013 and 2014. By analyzing the 137 atmospheric samples, the results showed that the annual mean atmospheric concentration of TFA was 1459±223 pg•m-3. TFA was mainly distributed in gaseous phase, for the concentration was 1396±225 pg•m-3, while that in particle phase was 62±8 pg•m-3. Considering the frequent occurrence of hazy weather in Beijing, the relationship between TFA and PM2.5 in atmosphere was analyzed. The correlation analysis shows that the proportion of particle phase in atmosphere concentration of TFA and mass concentration of PM2.5 are positively correlated with each other (P<0.001), indicating the particles have an absorption effect on TFA. At the same time, when mass concentration of PM2.5 in atmosphere is high, atmospheric concentration of TFA is relatively low. According to the correlation analysis, mass concentration of PM2.5 and atmospheric concentration of TFA are negatively correlated with each other (P=0.005). The main reason is very likely that particle's extinction for light can be enhanced as particle level rises, which causes TFA precursors photolysis to weaken. The results indicate that PM2.5 has a significant impact on TFA.

  12. Emissions inventory of PM2.5 trace elements across the United States.

    PubMed

    Reff, Adam; Bhave, Prakash V; Simon, Heather; Pace, Thompson G; Pouliot, George A; Mobley, J David; Houyoux, Marc

    2009-08-01

    This paper presents the first National Emissions Inventory (NEI) of fine particulate matter (PM2.5) that includes the full suite of PM2.5 trace elements (atomic number > 10) measured at ambient monitoring sites across the U.S. PM2.5 emissions in the NEI were organized and aggregated into a set of 84 source categories for which chemical speciation profiles are available (e.g., Unpaved Road Dust Agricultural Soil, Wildfires). Emission estimates for ten metals classified as Hazardous Air Pollutants (HAP) were refined using data from a recent HAP NEI. All emissions were spatially gridded, and U.S. emissions maps for dozens of trace elements (e.g., Fe, Ti) are presented for the first time. Nationally, the trace elements emitted in the highest quantities are silicon (3.8 x 10(5) ton/yr), aluminum (1.4 x 10(5) ton/yr), and calcium (1.3 x 10(5) ton/yr). Our chemical characterization of the PM2.5 inventory shows that most of the previously unspeciated emissions are comprised of crustal elements, potassium, sodium, chlorine, and metal-bound oxygen. This work also reveals that the largest PM2.5 sources lacking specific speciation data are off-road diesel-powered mobile equipment, road construction dust, marine vessels, gasoline-powered boats, and railroad locomotives. PMID:19731678

  13. Spatial modeling of PM2.5 concentrations with a multifactoral radial basis function neural network.

    PubMed

    Zou, Bin; Wang, Min; Wan, Neng; Wilson, J Gaines; Fang, Xin; Tang, Yuqi

    2015-07-01

    Accurate measurements of PM2.5 concentration over time and space are especially critical for reducing adverse health outcomes. However, sparsely stationary monitoring sites considerably hinder the ability to effectively characterize observed concentrations. Utilizing data on meteorological and land-related factors, this study introduces a radial basis function (RBF) neural network method for estimating PM2.5 concentrations based on sparse observed inputs. The state of Texas in the USA was selected as the study area. Performance of the RBF models was evaluated by statistic indices including mean square error, mean absolute error, mean relative deviation, and the correlation coefficient. Results show that the annual PM2.5 concentrations estimated by the RBF models with meteorological factors and/or land-related factors were markedly closer to the observed concentrations. RBF models with combined meteorological and land-related factors achieved best performance relative to ones with either type of these factors only. It can be concluded that meteorological factors and land-related factors are useful for articulating the variation of PM2.5 concentration in a given study area. With these covariate factors, the RBF neural network can effectively estimate PM2.5 concentrations with acceptable accuracy under the condition of sparse monitoring stations. The improved accuracy of air concentration estimation would greatly benefit epidemiological and environmental studies in characterizing local air pollution and in helping reduce population exposures for areas with limited availability of air quality data.

  14. Emissions inventory of PM2.5 trace elements across the United States

    SciTech Connect

    Adam Reff; Prakash V. Bhave; Heather Simon; Thompson G. Pace; George A. Pouliot; J. David Mobley; Marc Houyoux

    2009-08-15

    This paper presents the first National Emissions Inventory (NEI) of fine particulate matter (PM2.5) that includes the full suite of PM2.5 trace elements (atomic number >10) measured at ambient monitoring sites across the U.S. PM2.5 emissions in the NEI were organized and aggregated into a set of 84 source categories for which chemical speciation profiles are available (e.g., Unpaved Road Dust, Agricultural Soil, Wildfires). Emission estimates for ten metals classified as Hazardous Air Pollutants (HAP) were refined using data from a recent HAP NEI. All emissions were spatially gridded, and U.S. emissions maps for dozens of trace elements (e.g., Fe, Ti) are presented for the first time. Nationally, the trace elements emitted in the highest quantities are silicon (3.8 x 10{sup 5} ton/yr), aluminium (1.4 x 10{sup 5} ton/yr), and calcium (1.3 x 10{sup 5} ton/yr). Our chemical characterization of the PM2.5 inventory shows that most of the previously unspeciated emissions are comprised of crustal elements, potassium, sodium, chlorine, and metal-bound oxygen. Coal combustion is the largest source of S, Se, Sr, Hg and primary sulfates. This work also reveals that the largest PM2.5 sources lacking specific speciation data are off-road diesel-powered mobile equipment, road construction dust, marine vessels, gasoline-powered boats, and railroad locomotives. 28 refs., 4 figs.

  15. The modifying effect of the building envelope on population exposure to PM2.5 from outdoor sources

    PubMed Central

    Taylor, J; Shrubsole, C; Davies, M; Biddulph, P; Das, P; Hamilton, I; Vardoulakis, S; Mavrogianni, A; Jones, B; Oikonomou, E

    2014-01-01

    A number of studies have estimated population exposure to PM2.5 by examining modeled or measured outdoor PM2.5 levels. However, few have taken into account the mediating effects of building characteristics on the ingress of PM2.5 from outdoor sources and its impact on population exposure in the indoor domestic environment. This study describes how building simulation can be used to determine the indoor concentration of outdoor-sourced pollution for different housing typologies and how the results can be mapped using building stock models and Geographical Information Systems software to demonstrate the modifying effect of dwellings on occupant exposure to PM2.5 across London. Building archetypes broadly representative of those in the Greater London Authority were simulated for pollution infiltration using EnergyPlus. In addition, the influence of occupant behavior on indoor levels of PM2.5 from outdoor sources was examined using a temperature-dependent window-opening scenario. Results demonstrate a range of I/O ratios of PM2.5, with detached and semi-detached dwellings most vulnerable to high levels of infiltration. When the results are mapped, central London shows lower I/O ratios of PM2.5 compared with outer London, an apparent inversion of exposure most likely caused by the prevalence of flats rather than detached or semi-detached properties. PMID:24713025

  16. Black carbon and particulate matter (PM2.5) concentrations in New York City's subway stations.

    PubMed

    Vilcassim, M J Ruzmyn; Thurston, George D; Peltier, Richard E; Gordon, Terry

    2014-12-16

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m(3), with 1 min average peaks >100 μg/m(3), while real time PM2.5 levels ranged from 35 to 200 μg/m(3). Mean EC levels ranged from 9 to 12.5 μg/m(3). At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m(3), respectively. This study shows that both BC soot and PM levels in NYC's subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted. PMID:25409007

  17. Black carbon and particulate matter (PM2.5) concentrations in New York City's subway stations.

    PubMed

    Vilcassim, M J Ruzmyn; Thurston, George D; Peltier, Richard E; Gordon, Terry

    2014-12-16

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m(3), with 1 min average peaks >100 μg/m(3), while real time PM2.5 levels ranged from 35 to 200 μg/m(3). Mean EC levels ranged from 9 to 12.5 μg/m(3). At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m(3), respectively. This study shows that both BC soot and PM levels in NYC's subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted.

  18. Autoregressive spatially varying coefficients model for predicting daily PM2.5 using VIIRS satellite AOT

    NASA Astrophysics Data System (ADS)

    Schliep, E. M.; Gelfand, A. E.; Holland, D. M.

    2015-12-01

    There is considerable demand for accurate air quality information in human health analyses. The sparsity of ground monitoring stations across the United States motivates the need for advanced statistical models to predict air quality metrics, such as PM2.5, at unobserved sites. Remote sensing technologies have the potential to expand our knowledge of PM2.5 spatial patterns beyond what we can predict from current PM2.5 monitoring networks. Data from satellites have an additional advantage in not requiring extensive emission inventories necessary for most atmospheric models that have been used in earlier data fusion models for air pollution. Statistical models combining monitoring station data with satellite-obtained aerosol optical thickness (AOT), also referred to as aerosol optical depth (AOD), have been proposed in the literature with varying levels of success in predicting PM2.5. The benefit of using AOT is that satellites provide complete gridded spatial coverage. However, the challenges involved with using it in fusion models are (1) the correlation between the two data sources varies both in time and in space, (2) the data sources are temporally and spatially misaligned, and (3) there is extensive missingness in the monitoring data and also in the satellite data due to cloud cover. We propose a hierarchical autoregressive spatially varying coefficients model to jointly model the two data sources, which addresses the foregoing challenges. Additionally, we offer formal model comparison for competing models in terms of model fit and out of sample prediction of PM2.5. The models are applied to daily observations of PM2.5 and AOT in the summer months of 2013 across the conterminous United States. Most notably, during this time period, we find small in-sample improvement incorporating AOT into our autoregressive model but little out-of-sample predictive improvement.

  19. THE RELATIONSHIP BETWEEN REAL-TIME AND TIME-INTEGRATED COARSE (2.5-10MM), INTERMEDIATE (1-2.5MM), AND FINE (<2.5MM) PARTICULATE MATTER IN THE LOS ANGELES BASIN

    EPA Science Inventory

    Population exposure to ambient particulate matter (PM) has received considerable attention due to the association between ambient particulate concentrations and mortality. Current toxicological and epidemiological studies and controlled human and animal exposures suggest that a...

  20. Assessment of Remotely Sensed AOD-based PM2.5 Data for the CDC Tracking Network

    NASA Astrophysics Data System (ADS)

    Hu, X.; Vaidyanathan, A.; Qualters, J.; Liu, Y.

    2012-12-01

    Fine particulate matter (PM2.5) is small enough to invade air pathways in the body, and numerous health studies have examined the adverse health effects associated with exposure to PM2.5. PM2.5 ambient air concentration measurements are available from EPA's Air Quality System (AQS); however, monitors are not located in every county and do not sample for PM2.5 on a daily schedule. To estimate PM2.5 at highly resolved geographic and time scales, CDC collaborated with EPA on the development of a hierarchical Bayesian (HB) model to predict daily PM2.5 concentrations for use in the Environmental Public Health Tracking Network (Tracking Network). Meanwhile, satellite-retrieved Aerosol Optical Depth (AOD) can be converted to ambient PM2.5 estimates. We present the evaluation of satellite PM2.5 against AQS-based and HB-based PM2.5 predictions for the Southeastern U.S., and assess the feasibility of generating county-level measures from satellite PM2.5 for use in the Tracking Network. The study area contains 3702 12 km x 12 km grid cells, 102 AQS monitors and accounts for approximately 24 million people. The completeness of AOD data in the study domain ranged between 40 - 63 %. AOD-based PM2.5 estimates correlate well (r >0.8) with AQS-based measurements at most monitor locations. Median absolute difference between HB- and satellite PM2.5 estimates was 0.1 microgram/m3 with an interquartile range of 2.3 microgram/m3. In conclusion, remotely sensed AOD-based estimates are available on a near real-time basis and could help generate daily PM2.5 estimates at the county-level. The processing of satellite data is computationally less intensive than executing the HB model. While there are several benefits to using AOD-based estimates, there are a few limitations: data availability is limited by cloud cover and other atmospheric factors; data completeness could vary with season. These limitations notwithstanding, AOD-based PM2.5 estimates could be used to generate measures that are

  1. PM2.5 Spatiotemporal Variations and the Relationship with Meteorological Factors during 2013-2014 in Beijing, China

    PubMed Central

    Wang, Chao; Xu, Qin; Wang, Wei; Luo, Yanxia; Tao, Lixin; Gao, Qi; Guo, Jin; Chen, Sipeng; Cao, Kai; Liu, Long; Gao, Ni; Liu, Xiangtong; Yang, Kun; Yan, Aoshuang; Guo, Xiuhua

    2015-01-01

    Objective Limited information is available regarding spatiotemporal variations of particles with median aerodynamic diameter < 2.5 μm (PM2.5) at high resolutions, and their relationships with meteorological factors in Beijing, China. This study aimed to detect spatiotemporal change patterns of PM2.5 from August 2013 to July 2014 in Beijing, and to assess the relationship between PM2.5 and meteorological factors. Methods Daily and hourly PM2.5 data from the Beijing Environmental Protection Bureau (BJEPB) were analyzed separately. Ordinary kriging (OK) interpolation, time-series graphs, Spearman correlation coefficient and coefficient of divergence (COD) were used to describe the spatiotemporal variations of PM2.5. The Kruskal-Wallis H test, Bonferroni correction, and Mann-Whitney U test were used to assess differences in PM2.5 levels associated with spatial and temporal factors including season, region, daytime and day of week. Relationships between daily PM2.5 and meteorological variables were analyzed using the generalized additive mixed model (GAMM). Results Annual mean and median of PM2.5 concentrations were 88.07 μg/m3 and 71.00 μg/m3, respectively, from August 2013 to July 2014. PM2.5 concentration was significantly higher in winter (P < 0.0083) and in the southern part of the city (P < 0.0167). Day to day variation of PM2.5 showed a long-term trend of fluctuations, with 2–6 peaks each month. PM2.5 concentration was significantly higher in the night than day (P < 0.0167). Meteorological factors were associated with daily PM2.5 concentration using the GAMM model (R2 = 0.59, AIC = 7373.84). Conclusion PM2.5 pollution in Beijing shows strong spatiotemporal variations. Meteorological factors influence the PM2.5 concentration with certain patterns. Generally, prior day wind speed, sunlight hours and precipitation are negatively correlated with PM2.5, whereas relative humidity and air pressure three days earlier are positively correlated with PM2.5. PMID

  2. Orbital-optimized MP2.5 and its analytic gradients: Approaching CCSD(T) quality for noncovalent interactions

    SciTech Connect

    Bozkaya, Uğur; Sherrill, C. David

    2014-11-28

    Orbital-optimized MP2.5 [or simply “optimized MP2.5,” OMP2.5, for short] and its analytic energy gradients are presented. The cost of the presented method is as much as that of coupled-cluster singles and doubles (CCSD) [O(N{sup 6}) scaling] for energy computations. However, for analytic gradient computations the OMP2.5 method is only half as expensive as CCSD because there is no need to solve λ{sub 2}-amplitude equations for OMP2.5. The performance of the OMP2.5 method is compared with that of the standard second-order Møller–Plesset perturbation theory (MP2), MP2.5, CCSD, and coupled-cluster singles and doubles with perturbative triples (CCSD(T)) methods for equilibrium geometries, hydrogen transfer reactions between radicals, and noncovalent interactions. For bond lengths of both closed and open-shell molecules, the OMP2.5 method improves upon MP2.5 and CCSD by 38%–43% and 31%–28%, respectively, with Dunning's cc-pCVQZ basis set. For complete basis set (CBS) predictions of hydrogen transfer reaction energies, the OMP2.5 method exhibits a substantially better performance than MP2.5, providing a mean absolute error of 1.1 kcal mol{sup −1}, which is more than 10 times lower than that of MP2.5 (11.8 kcal mol{sup −1}), and comparing to MP2 (14.6 kcal mol{sup −1}) there is a more than 12-fold reduction in errors. For noncovalent interaction energies (at CBS limits), the OMP2.5 method maintains the very good performance of MP2.5 for closed-shell systems, and for open-shell systems it significantly outperforms MP2.5 and CCSD, and approaches CCSD(T) quality. The MP2.5 errors decrease by a factor of 5 when the optimized orbitals are used for open-shell noncovalent interactions, and comparing to CCSD there is a more than 3-fold reduction in errors. Overall, the present application results indicate that the OMP2.5 method is very promising for open-shell noncovalent interactions and other chemical systems with difficult electronic structures.

  3. Estimation of anthropogenic PM2.5 emissions over Asian mega cities by integrating remote sensing and modeling

    NASA Astrophysics Data System (ADS)

    Kishi, H.; Takeuchi, W.; Sawada, H.

    2011-12-01

    Particulate matter whose aerodynamic diameter is less than 2.5 um (PM2.5) is one of the major pollutants that affect human health with causing asthma and even cancer. Emission standards for PM2.5 are establishing only in some countries and regions mainly because it is difficult to understand the atmospheric behaviors of PM2.5 spatially and temporally. This study aims to estimate atmospheric conditions focusing on PM2.5 with integrating remote sensing measurement and model estimation with bottom-up approach over global mega cities. Firstly, emitted PM2.5 is estimated by bottom-up approach modeling according to emissions sources such as exhaust emissions and biomass burning from 2000 to 2010 over global scale. They are estimated by developed model with paper review and land cover properties obtained by satellite measurements. Exhaust emission PM2.5 is estimated by total numbers of diesel vehicles in use, the number of population and emission standards regulated by governmental raw. Biomass burning PM2.5 is estimated by the number of hot spots detected by Moderate resolution imaging spectroradiometer (MODIS), fuel loading equivalent to the amount of field biomass, combustion factors estimated by vegetation moisture conditions and PM2.5 emission factors. Secondly, estimation errors of estimated PM2.5 emissions are evaluated by comparing reported PM2.5 emission inventories spatially and temporally. Black carbon and Organic carbon emissions estimated by Streets and REAS emission inventory are employed to compare model estimated PM2.5. Thirdly, integrated exhaust emissions and biomass burning PM2.5 is compared with MODIS Aerosol Optical Depth (AOD) measurement which is equivalent to total amount of PM2.5. Spatio-temporal patterns are analyzed between model estimated and satellite measured PM2.5. In case of Asian regions Easter than India, it is found that the highest PM2.5 concentration is observed in Hanoi 3.2 times higher than that in Tokyo over Asian mega cities

  4. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2000-10-01

    This report summarizes observations and tentative conclusions drawn from evaluations of the data captured to date from the operation of the ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania, and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the upper Ohio River Valley region through the collection of chemically resolved or speciated data.

  5. On relationship between aerosols and PM2.5

    NASA Astrophysics Data System (ADS)

    Sano, Itaru; Mukai, Sonoyo; Nakata, Makiko

    2015-04-01

    Since aerosol optical thickness (AOT) is a key parameter of aerosols and description of the Earth's radiation budget, it is widely measured from ground sun photometer network NASA/AERONET [Holben et al., 1998] and from satellite. Fine and surface level aerosol particle called PM2.5, whose diameter is 2.5 μ m or less, is a well-known parameter for understanding polluted level of air. Smirnov et al. reported a good agreement between ground based AERONET AOT (870 nm) and dust concentrations at Barbados [Smirnov et al., 2000]. Wang and Christopher founded a good correlation between satellite based MODIS AOT product and PM2.5 in Alabama area [Wang and 2003]. Long range transported dusts, particularly Asian dust events, are easy to change the vertical profile of aerosol extinction. The vertical profile is important to estimate PM information because both AOT information measured from ground or satellite are integrated value of aerosol extinction from ground to space, i.e. columnar AOT. Thus, we have also proposed correlations between ground level PM2.5 and AERONET AOT (670 nm) in two cases of ordinary air condition and dusty days [Sano et al., 2010]. In this work, we investigate the relationship between PM2.5 and AERONET AOT considering LIDAR measurements. Note that all of instruments are set up at the roof of the University building (50 m) and collocated in 10 m area. Surface-level AOT is derived from AERONET AOT multiplied by an averaged vertical aerosol extinction given by LIDAR. Note that the definition of surface-level AOT in this work is assumed as AOT up to 500 m height. Introduction of surface-level AOT enables to avoid the contamination of dusty aerosol signal existing at high altitude from columnar AOT. The cloud aerosol imager (CAI) on GOSAT satellite has four observing wavelengths, 380, 670, 870 nm, and 1.6 μ m. In this work three channels are selected to estimate aerosol information. Look-up table (LUT) method is applied to estimate the optical properties

  6. PM2.5 and survival among older adults: Effect modification by particulate composition

    PubMed Central

    Kioumourtzoglou, Marianthi-Anna; Austin, Elena; Koutrakis, Petros; Dominici, Francesca; Schwartz, Joel; Zanobetti, Antonella

    2015-01-01

    Background Fine particulate (PM2.5) air pollution has been consistently linked to survival, but reported effect estimates are geographically heterogeneous. Exposure to different types of particle mixtures may explain some of this variation. Methods We used k-means cluster analyses to identify cities with similar pollution profiles, (i.e. PM2.5 composition) across the US. We examined the impact of PM2.5 on survival, and its variation across clusters of cities with similar PM2.5 composition, among Medicare enrollees in 81 US cities (2000–2010). We used time-varying annual PM2.5 averages, measured at ambient central monitoring sites, as the exposure of interest. We ran by-city Cox models, adjusting for individual data on previous cardiopulmonary-related hospitalizations and stratifying by follow-up time, age, gender and race. This eliminates confounding by factors varying across cities and long-term trends, focusing on year-to-year variations of air pollution around its city-specific mean and trend. We then pooled the city-specific effects using a random effects meta-regression. In this second stage, we also assessed effect modification by cluster membership and estimated cluster-specific PM2.5 effects. Results We followed more than 19 million subjects and observed more than 6 million deaths. We found a harmful impact of annual PM2.5 concentrations on survival (HR = 1.11 [95% confidence interval = 1.01–1.23] per 10 µg/m3). This effect was modified by particulate composition, with higher effects observed in clusters containing high concentrations of nickel, vanadium and sulfate. For instance, our highest effect estimate was observed in cities with harbors in the Northwest, characterized by high nickel, vanadium and elemental carbon concentrations (1.9 [1.1–3.3]). We observed null or negative associations in clusters with high oceanic and crustal particles. Conclusions To our knowledge, this is the first study to examine the association between PM2.5 composition

  7. Men Face Greater Risk of Cardiac Arrest

    MedlinePlus

    ... page: https://medlineplus.gov/news/fullstory_159651.html Men Face Greater Risk of Cardiac Arrest: Study Heart ... 30, 2016 THURSDAY, June 30, 2016 (HealthDay News) -- Men are significantly more likely to have their heart ...

  8. Ambient Fine Particulate (PM2.5) Air Pollution Attributable to Household Cooking Fuel in Asia

    NASA Astrophysics Data System (ADS)

    Chafe, Z.; Mehta, S.; Smith, K. R.

    2011-12-01

    Using the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model, hosted by the International Institute for Applied Systems Analysis (IIASA), we estimate the proportion of fine particulate ambient air pollution (PM2.5) attributable to household fuel use for cooking in Asia. This analysis considers primary anthropogenic PM2.5 emissions in two years: 1990 and 2005. Only emissions from household cooking fuels-not heating or lighting-are considered. Due to data availability, this analysis focuses solely on Asian countries, notably India and China which are home to about half of the households using solid fuel use worldwide. Forest and grassland fires, dust, and other "natural" particle sources were omitted from this analysis. The impact of emission sources on secondary particles from aerosol precursors was not determined. In China, the proportion of total primary anthropogenic PM2.5 attributable to household cooking decreased from 44% to 31% between 1990 and 2005. In India, the percent of primary anthropogenic PM2.5 emissions attributable to household cooking decreased from 55% to 49% between 1990 and 2005. Total mass change in primary anthropogenic PM2.5 emissions was much more variable by state in India, between 1990 and 2005, than by province in China (where there was a general downward trend in the total mass emitted). Similarly, growth in industrial emissions was much more variable at the sub-national level, between 1990 and 2005, in India than in China. Energy production played a more prominent role in the growth of primary anthropogenic PM2.5 emissions in India than it did in China. Forward-looking GAINS scenarios show that the contribution of household cooking to total primary anthropogenic PM2.5 emissions is much greater than that from on-road transport in India and China between 1990 and 2030. On-road cars, trucks, and other transport vehicles are, however, the cause of important pollutants other than PM2.5 (as are as cooking stoves that do

  9. Assessment of Population and Microenvironmental Exposure to Fine Particulate Matter (PM2.5)

    NASA Astrophysics Data System (ADS)

    Jiao, Wan

    A positive relationship exists between fine particulate matter (PM 2.5) exposure and adverse health effects. PM2.5 concentration-response functions used in the quantitative risk assessment were based on findings from human epidemiological studies that relied on areawide ambient concentrations as surrogate for actual ambient exposure, which cannot capture the spatial and temporal variability in human exposures. The goal of the study is to assess inter-individual, geographic and seasonal variability in population exposures to inform the interpretation of available epidemiological studies, and to improve the understanding of how exposure-related factors in important exposure microenvironments contribute to the variability in individual PM2.5 exposure. Typically, the largest percentage of time in which an individual is exposed to PM2.5 of ambient origin occurs in indoor residence, and the highest ambient PM2.5 concentrations occur in transportation microenvironments because of the proximity to on-road traffic emissions. Therefore, indoor residence and traffic-related transportation microenvironments were selected for further assessment in the study. Population distributions of individual daily PM2.5 exposures were estimated for the selected regions and seasons using the Stochastic Human Exposure and Dose Simulation Model for Particulate Matter (SHEDS-PM). For the indoor residence, the current practice by assuming the entire residence to be one large single zone for calculating the indoor residential PM 2.5 concentration was evaluated by applying an indoor air quality model, RISK, to compare indoor PM2.5 concentrations between single-zone and multi-zone scenarios. For the transportation microenvironments, one field data collection focused on in-vehicle microenvironment and was conducted to quantify the variability in the in-vehicle PM2.5 concentration with respect to the outside vehicle concentration for a wide range of conditions that affect intra-vehicle variability

  10. Impact of urbanization level on urban air quality: a case of fine particles (PM(2.5)) in Chinese cities.

    PubMed

    Han, Lijian; Zhou, Weiqi; Li, Weifeng; Li, Li

    2014-11-01

    We examined and compared PM2.5 concentrations in urban and the surrounding regions, and further investigated the impact of urbanization on urban PM2.5 concentrations at the Chinese prefectures. Annual PM2.5 concentrations in most prefectures were greater than 10 μg/m(3), the air quality guideline of the World Health Organization. Those prefectures were mainly distributed along the east coast and southeast of Sichuan province; The urban PM2.5 concentrations ( [Formula: see text] ) in 85 cities were greater than (>10 μg/m(3)) those in the surrounding area. Those cities were mainly located in the Beijing-Sichuan and Shanghai-Guangxi belts. In addition, [Formula: see text] was less than (<0 μg/m(3)) that in surrounding areas in only 41 prefectures, which were located in western China or nearby mega cities; Significant positive correlations were found between [Formula: see text] and urban population (R(2) = 0.99, P < 0.05), and between [Formula: see text] and urban second industry fraction (R(2) = 0.71, P < 0.05), suggesting that urbanization had considerable impact on PM2.5 concentrations.

  11. Reactivity of 1,2,5,6-Tetrathiocines

    NASA Astrophysics Data System (ADS)

    Wrixon, Justin D.

    This thesis describes selected chemistry of 1,2,5,6-tetrathiocines, 8-membered heterocycles containing four S atoms which can be considered as bis(disulfides). Chapter 1 provides a literature review of the existing chemistry of 1,2,5,6-tetrathiocines. Chapters 2 -- 4 examine the oxidative addition chemistry of tetrathiocines to zero-valent group 10 metal complexes in the presence of an auxiliary phosphine ligand under microwave conditions to afford nickel, palladium and platinum dithiolate complexes. These chapters probe the effect of the metal (Chapter 2), the auxiliary phosphine (Chapter 3) and the tetrathiocine (Chapter 4) on the outcome of the chemical reaction, leading to a range of mono-, di- and hexa-metallic complexes which have been fully characterized by multinuclear NMR, mass spectroscopy and X-ray diffraction. Finally, Chapter 6 describes the use of tetrathiocines as precursors to 1,3,2-benzodithiazyl (BDTA) radicals and two new dithiazolyl radicals have been isolated and characterized by X-ray diffraction and EPR spectroscopy.

  12. ADVANCES IN CONTROL OF PM2..5 AND PM2..5 PRECURSORS GENERATED BY THE COMBUSTION OF PULVERIZED COAL

    EPA Science Inventory

    Particulate matter smaller than 2.5 micrometers in aerodynamic diameter (PM2.5) is of concern due to adverse health effects associated with elevated ambient mass concentrations of PM2.5. PM2.5 from coal-fired utility boilers is composed of directly emitted (primary) particles and...

  13. PM2.5 Indoor Air Quality at Two Sites in London Ontario - A Case Study

    NASA Astrophysics Data System (ADS)

    Mates, A. V.; Xu, X.; Gilliland, J.; Maltby, M. J.

    2010-12-01

    Studies have shown an association between ambient fine particulate matter (PM2.5) and health impacts, particularly for the elderly and children. As part of a larger study, PM2.5 concentrations were measured using the DustTrak (Model 8520, TSI, St. Paul, MN, USA) at two schools within the city of London, Ontario (Canada). Site A was in a suburban environment while site B was in an urban setting. Monitoring took place for 3 weeks during winter (Feb. 16 - Mar. 8) and 3 weeks during spring (May 05 - 25) of 2010. The winter campaign monitored indoor PM2.5 only, while the spring campaign added outdoor monitors (PM2.5 and CO2) after the first week. Ten min. concentrations were used for analysis. Indoor measurements were split into weekday and weekend. For the same time interval, the outdoor concentrations showed mean values of 18 and 21 μg/m3 for sites A & B, respectively, both under the Canada Wide Standard of 30 μg/m3. Measurements at the two sites showed good associations (R^2 = 0.44), during the spring campaign. This indicates that the outdoor PM2.5 had similar sources. For indoor concentrations, Site B showed a significantly different mean concentration 5 times higher compared to site A during the winter ( 8.1 vs. 1.5 μg/m3 ) and 3 times higher (11.9 vs. 3.7 μg/m3) during the spring campaign. Since the outdoor concentrations were similar the large difference in indoor concentrations could be attributed to the following factors: site B being an older building, and the different physical characteristics between the two sites. The spring measurements showed an increase of 50% from weekday to weekend for site A and 22% for site B. The higher level of PM2.5 during weekends is possibly due to the infiltration of outdoor air while the ventilation/filtration system is shut off. During the winter campaign, Site A showed a 14% higher concentration during weekdays compared to weekends while site B weekend concentrations were 17% higher compared to weekday, which will be

  14. Determination and source identification of priority polycyclic aromatic hydrocarbons in PM2.5 in Taiyuan, China

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Xie, Jingfang; Wang, Zhentao; Zhao, Lijuan; Zhang, Hong; Li, Meng

    2016-09-01

    Sixteen polycyclic aromatic hydrocarbons (PAHs) present in PM2. 5 were analyzed in 2012 in Taiyuan (China) using high performance liquid chromatography (HPLC) with fluorescence and ultraviolet detectors. The average daily mass concentrations of ΣPAHs in different seasons ranged from 10.36 ng/m3 to 215.93 ng/m3 and had strong seasonal variation, with highest values in winter and lowest in summer. Over the whole year, PAHs appeared in the following order of frequency: 4-ring > 6-ring > 5-ring > 3-ring; in winter, the percentage of 4-ring PAHs was the highest (62.68%), while in summer, the percentages of 5-ring and 6-ring PAHs (cumulative total of 50.57%) were higher. The ratio method was employed to investigate potential source categories of PAHs in PM2.5 in Taiyuan, with data suggesting that the main PAH sources are coal and wood combustion and vehicle emissions. Finally, a risk assessment of PAHs was performed based on benzo(a)pyrene equivalent (BaPeq) values and individual cancer risk ratios, with results suggesting that the toxicity of PAHs was high during winter and spring time in Taiyuan. The values of incremental lifetime cancer risk (ILCR) induced by whole year inhalation exposure(Ri) for all age groups were larger than 10- 6 in spring and winter, while Ri values for male and female adults in summer and autumn were also larger than 10- 6, indicating high potential carcinogenic risk. During the same season, the ILCR of adults was greater than that of other age groups and that of females was a little higher than of males. With respect to the season, the ranking of ILCR in decreasing order was as follows: winter, spring, autumn, and summer.

  15. Measuring in-cabin school bus tailpipe and crankcase PM2.5: a new dual tracer method.

    PubMed

    Ireson, Robert G; Ondov, John M; Zielinska, Barbara; Weaver, Christopher S; Easter, Michael D; Lawson, Douglas R; Hesterberg, Thomas W; Davey, Mark E; Liu, L-J Sally

    2011-05-01

    Exposures of occupants in school buses to on-road vehicle emissions, including emissions from the bus itself, can be substantially greater than those in outdoor settings. A dual tracer method was developed and applied to two school buses in Seattle in 2005 to quantify in-cabin fine particulate matter (PM2.5) concentrations attributable to the buses' diesel engine tailpipe (DPMtp) and crankcase vent (PMck) emissions. The new method avoids the problem of differentiating bus emissions from chemically identical emissions of other vehicles by using a fuel-based organometallic iridium tracer for engine exhaust and by adding deuterated hexatriacontane to engine oil. Source testing results showed consistent PM:tracer ratios for the primary tracer for each type of emissions. Comparisons of the PM:tracer ratios indicated that there was a small amount of unburned lubricating oil emitted from the tailpipe; however, virtually no diesel fuel combustion products were found in the crankcase emissions. For the limited testing conducted here, although PMck emission rates (averages of 0.028 and 0.099 g/km for the two buses) were lower than those from the tailpipe (0.18 and 0.14 g/km), in-cabin PMck concentrations averaging 6.8 microg/m3 were higher than DPMtp (0.91 microg/m3 average). In-cabin DPMtp and PMck concentrations were significantly higher with bus windows closed (1.4 and 12 microg/m3, respectively) as compared with open (0.44 and 1.3 microg/m3, respectively). For comparison, average closed- and open-window in-cabin total PM2.5 concentrations were 26 and 12 microg/m3, respectively. Despite the relatively short in-cabin sampling times, very high sensitivities were achieved, with detection limits of 0.002 microg/m3 for DPMtp and 0.05 microg/m3 for PMck. PMID:21608489

  16. Air Pollution Exposure Model for Individuals (EMI) in Health Studies: Evaluation for Ambient PM2.5 in Central North Carolina

    EPA Science Inventory

    Air pollution health studies of fine particulate matter (diameter ≤2.5 μm, PM2.5) often use outdoor concentrations as exposure surrogates. Failure to account for variability of indoor infiltration of ambient PM2.5 and time indoors can induce exposure errors. We developed an...

  17. Characterization of the solvent extractable organic compounds in PM2.5 aerosols in Hong Kong

    NASA Astrophysics Data System (ADS)

    Zheng, Mei; Fang, Ming; Wang, Fu; To, K. L.

    The results from a year-long monthly study of the solvent extractable organic compounds (SEOC) in PM2.5 of the ambient aerosols in Hong Kong are reported. A total of 18 samples were analyzed. The extracted organic compounds were separated into four major fractions ( n-alkanes, fatty acids, alkanols and PAHs (polycyclic aromatic hydrocarbons)) and identified with GC-MS (gas chromatography-mass spectrometry). The percentage of each fraction in total yield is as follows: fatty acids at 46-80%, alkanes at 10-34%, alkanols at 4-21%, and PAHs at 1-6%. Compared to the TSP (total suspended particulates) samples from our previous studies, the PAH fraction was higher in PM2.5 than TSP (0.5-2.5%). The bias of PAHs in PM2.5 suggests potential implications in health impact because PM2.5 is respirable. The total yield (defined as the sum of the four fractions) in PM2.5 was in the range of 56.4-233.6 ng m -3. The sources of SEOC in PM2.5 could be attributed to vehicular, biogenic and microbial origins. On the average, 79% of the alkanes in PM2.5 came from vehicular emissions. U: R (ratio of unresolved to resolved components), an index to assess the magnitude of petroleum residues in aerosols, exhibited higher values in PM2.5 (average 3.2, range 1.0-5.9) than TSP (average 2.4, range 1.1-3.3). CPI (carbon preference index) of alkanes showed an inverse relationship with U: R, and a positive correlation with the percentage of alkanes from higher plant wax. Although U: R and CPI have been widely used as indices in source apportionment, their effectiveness was demonstrated for the first time from the statistical point of view in this paper. It was discovered that the CPI=1 (a characteristic of petroleum hydrocarbons) envelope and Cmax shifted towards lower carbon numbers in winter, suggesting there was more contribution from vehicular emission. PAHs had the following range 0.7-12.2 ng m -3. The positive correlation with benzo(ghi)perylene suggested that they were of vehicular origin

  18. Comparison between 2.5D and 3D simulations of coronal mass ejections

    NASA Astrophysics Data System (ADS)

    Jacobs, C.; van der Holst, B.; Poedts, S.

    2007-07-01

    Context: The shocks and magnetic clouds related to Coronal Mass Ejections (CMEs) in the solar corona and interplanetary space (IP) play an important role in the study of space weather. In order to study the evolution of these IP shocks, numerical simulations of a simplified CME model were performed. Aims: In an earlier study, the effect of the background wind on the evolution of interplanetary shock waves was investigated, where the computations were carried out under the assumption of axial symmetry. The assumption of axial symmetry might be a good approach for the solar corona under conditions of solar minimum, but for the study of CMEs this assumption is definitely no longer valid as CMEs possess clearly a fully three dimensional (3D) structure. From this perspective, the previous simulations were repeated, but now in a three dimensional set-up in order to point out the differences between the 2.5D and 3D simulations and to check the quality and reliability of the 2.5D simulations. Methods: The computations were performed in the framework of ideal magnetohydrodynamics (MHD) and to advance the ideal MHD equations in time a parallel finite volume code with explicit upwind solver was used. The shock waves are generated in a similar way in both the 3D and 2.5D simulations, namely by a simple density-blob model. The 3D and 2.5D simulations are all performed with the same numerical methods and on comparable grids, such that the differences between the simulations are purely due to the dimensionality of the problem, and/or the initial parameters for the CME generation. Results: Three different axisymmetric simulations of CME propagation are compared with the fully three dimensional computation. The 2.5D simulations differ from each other in the parameters used for CME initiation. In a first simulation, the same initial parameters as for the 3D case were taken, in a second simulation the initial amount of mass in the 2.5D and 3D CME was the same, and in a third

  19. AMBIENT PM2.5 SAMPLING AND ANALYSIS

    SciTech Connect

    Unknown

    2001-04-30

    This is the third semi-annual technical progress report summarizing observations and tentative conclusions drawn from evaluations of the data captured to date from the operation of the ambient PM{sub 2.5} speciation sites in a geographical area encompassing southeastern Ohio, western Pennsylvania, and northwestern West Virginia. The overall goal of this program, called the Upper Ohio River Valley Project (UORVP), is to better understand the relationship between coal-based power system emissions and ambient air quality in the upper Ohio River Valley region through the collection of chemically resolved or speciated data. In order to provide a ''stand alone'' document, this report contains updated versions of Section 1 (Introduction) and Section 2 (Experimental) in their entirety from the first report.

  20. A compact 2.5-Kelvin closed-cycle refrigerator

    NASA Astrophysics Data System (ADS)

    Britcliffe, Mike

    A helium refrigerator utilizing the Gifford-McMahon/Joule-Thomson cycle was designed and tested to demonstrate the feasibility of using small closed-cycle refrigerators as an alternative to batch filled-cryostats for operating temperatures below 4 K. The systems could be used to cool low-noise microwave maser amplifiers located in large parabolic antennas. These antennas tilt vertically, making conventional liquid-filled dewars difficult to use. The system could also be used for a nontilting beam waveguide antenna to reduce the helium consumption of a liquid helium cryostat. The prototype system is adjustable to provide 700 milliwatts of cooling at 2.5 K to 3 watts at 4.3 K. The performance of the unit is not significantly affected by operation in any physical orientation.

  1. Asymmetric transformations of achiral 2,5-cyclohexadienones

    PubMed Central

    Kalstabakken, Kyle A.; Harned, Andrew M.

    2014-01-01

    Cyclohexadienones are versatile platforms for performing asymmetric synthesis as evidenced by the numerous natural product syntheses that exploit their diverse reactivity profile. However, there are few general methods available for the direct asymmetric synthesis of chiral cyclohexadienones. To circumvent this problem, several researchers have developed catalytic asymmetric methods that employ readily available achiral 2,5-cyclohexadienones as substrates. Many of these reactions are desymmetrizations in which one of the enantiotopic alkenes of an achiral dienone is transformed. Others involve selective reaction at one alkene of an unsymmetrically substituted, achiral dienone. This review will cover advances in this area over the last 20 years and the application of these strategies in complex molecule synthesis. PMID:26688596

  2. On-road PM2.5 pollution exposure in multiple transport microenvironments in Delhi

    NASA Astrophysics Data System (ADS)

    Goel, Rahul; Gani, Shahzad; Guttikunda, Sarath K.; Wilson, Daniel; Tiwari, Geetam

    2015-12-01

    PM2.5 pollution in Delhi averaged 150 μg/m3 from 2012 through 2014, which is 15 times higher than the World Health Organization's annual-average guideline. For this setting, we present on-road exposure of PM2.5 concentrations for 11 transport microenvironments along a fixed 8.3-km arterial route, during morning rush hour. The data collection was carried out using a portable TSI DustTrak DRX 8433 aerosol monitor, between January and May (2014). The monthly-average measured ambient concentrations varied from 130 μg/m3 to 250 μg/m3. The on-road PM2.5 concentrations exceeded the ambient measurements by an average of 40% for walking, 10% for cycle, 30% for motorised two wheeler (2W), 30% for open-windowed (OW) car, 30% for auto rickshaw, 20% for air-conditioned as well as for OW bus, 20% for bus stop, and 30% for underground metro station. On the other hand, concentrations were lower by 50% inside air-conditioned (AC) car and 20% inside the metro rail carriage. We find that the percent exceedance for open modes (cycle, auto rickshaw, 2W, OW car, and OW bus) reduces non-linearly with increasing ambient concentration. The reduction is steeper at concentrations lower than 150 μg/m3 than at higher concentrations. After accounting for air inhalation rate and speed of travel, PM2.5 mass uptake per kilometer during cycling is 9 times of AC car, the mode with the lowest exposure. At current level of concentrations, an hour of cycling in Delhi during morning rush-hour period results in PM2.5 dose which is 40% higher than an entire-day dose in cities like Tokyo, London, and New York, where ambient concentrations range from 10 to 20 μg/m3.

  3. An empirical relationship between PM(2.5) and aerosol optical depth in Delhi Metropolitan.

    PubMed

    Kumar, Naresh; Chu, Allen; Foster, Andrew

    2007-07-01

    Atmospheric remote sensing offers a unique opportunity to compute indirect estimates of air quality, which are critically important for the management and surveillance of air quality in megacities of developing countries, particularly in India and China, which have experienced elevated concentration of air pollution but lack adequate spatial-temporal coverage of air pollution monitoring. This article examines the relationship between aerosol optical depth (AOD) estimated from satellite data at 5 km spatial resolution and the mass of fine particles ≤2.5 μm in aerodynamic diameter (PM(2.5)) monitored on the ground in Delhi Metropolitan where a series of environmental laws have been instituted in recent years.PM(2.5) monitored at 113 sites were collocated by time and space with the AOD computed using the data from Moderate Resolution Imaging Spectroradiometer (MODIS onboard the Terra satellite). MODIS data were acquired from NASA's Goddard Space Flight Center Earth Sciences Distributed Active Archive Center (DAAC). Our analysis shows a significant positive association between AOD and PM(2.5). After controlling for weather conditions, a 1% change in AOD explains 0.52±0.202% and 0.39±0.15% change in PM(2.5) monitored within ±45 and 150 min intervals of AOD data. This relationship will be used to estimate air quality surface for previous years, which will allow us to examine the time-space dynamics of air pollution in Delhi following recent air quality regulations, and to assess exposure to air pollution before and after the regulations and its impact on health.

  4. Comparative evaluation of the impact of WRF/NMM and WRF/ARW meteorology on CMAQ simulations for PM2.5 and its related precursors during the 2006 TexAQS/GoMACCS study

    NASA Astrophysics Data System (ADS)

    Yu, S.; Mathur, R.; Pleim, J.; Pouliot, G.; Wong, D.; Eder, B.; Schere, K.; Gilliam, R.; Rao, S. T.

    2011-12-01

    This study presents a comparative evaluation of the impact of WRF-NMM and WRF-ARW meteorology on CMAQ simulations of PM2.5, its composition and related precursors over the eastern United States with the intensive observations obtained by aircraft (NOAA P-3), ship and surface monitoring networks (AIRNow, IMPROVE, CASTNet and STN) during the 2006 TexAQS/GoMACCS study. The results at the AIRNow surface sites show that both ARW-CMAQ and NMM-CMAQ reproduced day-to-day variations of observed PM2.5 and captured the majority of observed PM2.5 within a factor of 2 with a NMB value of -0.4% for ARW-CMAQ and -18% for NMM-CMAQ. Both models performed much better at the urban sites than at the rural sites, with greater underpredictions at the rural sites. Both models consistently underestimated the observed PM2.5 at the rural IMPROVE sites by -1% for the ARW-CMAQ and -19% for the NMM-CMAQ. The greater underestimations of SO42-, OC and EC by the NMM-CMAQ contributed to increased underestimation of PM2.5 at the IMPROVE sites. The NMB values for PM2.5 at the STN urban sites are 15% and -16% for the ARW-CMAQ and NMM-CMAQ, respectively. The underestimation of PM2.5 at the STN sites by the NMM-CMAQ mainly results from the underestimations of the SO42-, NH4+ and TCM components, whereas the overestimation of PM2.5 at the STN sites by the ARW-CMAQ results from the overestimations of SO42-, NO3-, and NH4+. The comparison with P-3 aircraft measurements reveals that both ARW-CMAQ and NMM-CMAQ have very similar model performance for vertical profiles for PM2.5 chemical components (SO42-, NH4+) and related gaseous species (HNO3, SO2, NH3, isoprene, toluene, terpenes) as both models used the same chemical mechanisms and emissions. The results of ship along the coast of southeastern Texas over the Gulf of Mexico show that both models captured the temporal variations and broad synoptic change seen in the observed HCHO and acetaldehyde with the means NMB <30% most of the time but they

  5. Comparative evaluation of the impact of WRF/NMM and WRF/ARW meteorology on CMAQ simulations for PM2.5 and its related precursors during the 2006 TexAQS/GoMACCS study

    NASA Astrophysics Data System (ADS)

    Yu, S.; Mathur, R.; Pleim, J.; Pouliot, G.; Wong, D.; Eder, B.; Schere, K.; Gilliam, R.; Rao, S. T.

    2012-05-01

    This study presents a comparative evaluation of the impact of WRF-NMM and WRF-ARW meteorology on CMAQ simulations of PM2.5, its composition and related precursors over the eastern United States with the intensive observations obtained by aircraft (NOAA WP-3), ship and surface monitoring networks (AIRNow, IMPROVE, CASTNet and STN) during the 2006 TexAQS/GoMACCS study. The results at the AIRNow surface sites show that both ARW-CMAQ and NMM-CMAQ reproduced day-to-day variations of observed PM2.5 and captured the majority of observed PM2.5 within a factor of 2 with a NMB value of -0.4% for ARW-CMAQ and -18% for NMM-CMAQ. Both models performed much better at the urban sites than at the rural sites, with greater underpredictions at the rural sites. Both models consistently underestimated the observed PM2.5 at the rural IMPROVE sites by -1% for the ARW-CMAQ and -19% for the NMM-CMAQ. The greater underestimations of SO42-, OC and EC by the NMM-CMAQ contributed to increased underestimation of PM2.5 at the IMPROVE sites. The NMB values for PM2.5 at the STN urban sites are 15% and -16% for the ARW-CMAQ and NMM-CMAQ, respectively. The underestimation of PM2.5 at the STN sites by the NMM-CMAQ mainly results from the underestimations of the SO42-, NH4+ and TCM components, whereas the overestimation of PM2.5 at the STN sites by the ARW-CMAQ results from the overestimations of SO42-, NO3-, and NH4+. The Comparison with WP-3 aircraft measurements reveals that both ARW-CMAQ and NMM-CMAQ have very similar model performance for vertical profiles for PM2.5 chemical components (SO42-, NH4+) and related gaseous species (HNO3, SO2, NH3, isoprene, toluene, terpenes) as both models used the same chemical mechanisms and emissions. The results of ship along the coast of southeastern Texas over the Gulf of Mexico show that both models captured the temporal variations and broad synoptic change seen in the observed HCHO and acetaldehyde with the means NMB <30% most of the time but they

  6. Analysis of airborne particulate matter (PM2.5) over Hong Kong using remote sensing and GIS.

    PubMed

    Shi, Wenzhong; Wong, Man Sing; Wang, Jingzhi; Zhao, Yuanling

    2012-01-01

    Airborne fine particulates (PM(2.5); particulate matter with diameter less than 2.5 μm) are receiving increasing attention for their potential toxicities and roles in visibility and health. In this study, we interpreted the behavior of PM(2.5) and its correlation with meteorological parameters in Hong Kong, during 2007-2008. Significant diurnal variations of PM(2.5) concentrations were observed and showed a distinctive bimodal pattern with two marked peaks during the morning and evening rush hour times, due to dense traffic. The study observed higher PM(2.5) concentrations in winter when the northerly and northeasterly winds bring pollutants from the Chinese mainland, whereas southerly monsoon winds from the sea bring fresh air to the city in summer. In addition, higher concentrations of PM(2.5) were observed in rush hours on weekdays compared to weekends, suggesting the influence of anthropogenic activities on fine particulate levels, e.g., traffic-related local PM(2.5) emissions. To understand the spatial pattern of PM(2.5) concentrations in the context of the built-up environment of Hong Kong, we utilized MODerate Resolution Imaging Spectroradiometer (MODIS) Aerosol Optical Thickness (AOT) 500 m data and visibility data to derive aerosol extinction profile, then converted to aerosol and PM(2.5) vertical profiles. A Geographic Information Systems (GIS) prototype was developed to integrate atmospheric PM(2.5) vertical profiles with 3D GIS data. An example of the query function in GIS prototype is given. The resulting 3D database of PM(2.5) concentrations provides crucial information to air quality regulators and decision makers to comply with air quality standards and in devising control strategies.

  7. Issues and results in the development of 2. 5 micron filament strand for the HEB

    SciTech Connect

    Seuntjens, J.M.; Capone, D.W. III.

    1991-03-01

    The High Energy Booster (HEB) ring which injects protons into the Superconducting Super Collider (SS) will be ramped with a cycle time on the order of 8 minutes. The current magnet design incorporates a strand with 2.5 {mu}m filaments to reduce the AC loss heating component due to the magnetization hysteresis. The reduced magnetization also makes the correction of the sextupole moment easier. Past experience has shown that Nb-Ti filaments in a copper matrix should have a spacing-to-diameter ratio (s/d) of 0.15 for good fabricability. For 2.5 {mu}m filaments, this results in a spacing on the order of 0.4 {mu}m at final wire size. A Cu-Mn alloy has replaced the copper between the filaments in prototype conductors to effectively eliminate proximity coupling between 2.5 {mu}m filaments which would otherwise occur with copper at this spacing. The resistivity of the material between the filaments is limited by the mean free path being equal to the filament spacing: therefore, cryogenic stability has not been compromised. This paper discusses design and process parameters in the development of 2.5 {mu}m filament conductor production. Data from current 2.5 {mu}m work from several vendors, some of which are on FFP-type contracts sponsored by the SSCL, are included to demonstrate how close industry is to meeting 2.5 {mu}m conductor needs. If the SSCL were unable to bring 2.5 {mu}m conductor into production within about two years' time, a fall-back HEB design with 6 {mu}m filament conductor would be utilized. Therefore, a strong emphasis on manufacturability is reflected in the key issues. The sole purpose of this paper is to establish a common level of understanding of fine filament needs of the SSC; therefore, the data will be purposely presented without vendor affiliation. The authors have paid careful attention to details to avoid the release of proprietary information in this paper. 6 refs., 3 figs., 1 tab.

  8. Recognition of 2',5'-linked oligoadenylates by human ribonuclease L: molecular dynamics study.

    PubMed

    Maláč, Kamil; Barvík, Ivan

    2014-04-01

    The capability of current MD simulations to be used as a tool in rational design of agonists of medically interesting enzyme RNase L was tested. Dimerization and enzymatic activity of RNase L is stimulated by 2',5'-linked oligoadenylates (pA₂₅A₂₅A; 2-5A). First, it was necessary to ensure that a complex of monomeric human RNase L and 25A was stable in MD simulations. It turned out that Glu131 had to be protonated. The non-protonated Glu131 caused dissociation of 2-5A from RNase L. Because of the atypical 2'-5' internucleotide linkages and a specific spatial arrangement of the 25A trimer, when a single molecule carries all possible conformers of the glycosidic torsion angle, several versions of the AMBER force field were tested. One that best maintained functionally important interactions of 25A and RNase L was selected for subsequent MD simulations. Furthermore, we wonder whether powerful GPUs are able to produce MD trajectories long enough to convincingly demonstrate effects of subtle perturbations of interactions between 25A and RNase L. Detrimental impacts of various point mutations of RNase L (R155A, F126A, W60A, K89A) on 2-5A binding were observed on a time scale of 200 ns. Finally, 2-5A analogues with a bridged 3'--O,4'--C-alkylene linkage (B) introduced into the adenosine units (A) were used to assess ability of MD simulations to distinguish on the time scale of hundreds of nanoseconds between agonists of RNase L (pA₂₅A₂₅B, pB₂₅A₂₅A, pB₂₅A₂₅B) and inactive analogs (pA₂₅B₂₅A, pA₂₅B₂₅B, pB₂₅B₂₅A, pB₂₅B₂₅B). Agonists were potently bound to RNase L during 200 ns MD runs. For inactive 2-5A analogs, by contrast, significant disruptions of their interactions with RNase L already within 100 ns MD runs were found. PMID:24633766

  9. The socioeconomic drivers of China’s primary PM2.5 emissions

    NASA Astrophysics Data System (ADS)

    Guan, Dabo; Su, Xin; Zhang, Qiang; Peters, Glen P.; Liu, Zhu; Lei, Yu; He, Kebin

    2014-01-01

    Primary PM2.5 emissions contributed significantly to poor air quality in China. We present an interdisciplinary study to measure the magnitudes of socioeconomic factors in driving primary PM2.5 emission changes in China between 1997-2010, by using a regional emission inventory as input into an environmentally extended input-output framework and applying structural decomposition analysis. Our results show that China’s significant efficiency gains fully offset emissions growth triggered by economic growth and other drivers. Capital formation is the largest final demand category in contributing annual PM2.5 emissions, but the associated emission level is steadily declining. Exports is the only final demand category that drives emission growth between 1997-2010. The production of exports led to emissions of 638 thousand tonnes of PM2.5, half of the EU27 annual total, and six times that of Germany. Embodied emissions in Chinese exports are largely driven by consumption in OECD countries.

  10. Hailstones across the Greater Sydney Metropolitan Area

    NASA Astrophysics Data System (ADS)

    Rasuly, A. A.; Cheung, K. K. W.; McBurney, B.

    2014-11-01

    This study addresses the recent climatology of hail occurrence in the Greater Metropolitan Severe Thunderstorm Warning Area (GMSTWA) of New South Wales, Australia, which is a sprawling suburban area, with a population of nearly 4.7 million and one of Australia's largest metropolis. The main objective is to highlight the recent temporal-spatial fluctuations of hailstone frequencies and magnitudes for each of recognized and vastly inhabited Local Government Areas (LGAs). The relevant hail event data from 1989 to 2013 were initially derived from the severe storm archive of Australian Bureau of Meteorology. A climatologically oriented GIS technique was applied in the examining and mapping procedure of all hail events and hail days reported throughout the study area. By applying a specific criterion, all severe hails (defined as 2 cm or more in diameter) were cautiously selected and then imported into the ArcGIS software for relevant analysis. Appropriate data layers were stored in a unique database to allow logical integration of the data directly into some geoprocessing functions, mainly for querying, analyzing and mapping purposes in a model-builder setting. The database includes 357 hailstones with sizes 2-11 cm and occurred in 169 hail days across the region during the past 25 years. The models have established that hailstones are neither temporally nor spatially uniform in magnitude throughout the study area. Temporal analysis indicated that most of hail events occurred predominately in the afternoons with peak time of 1-5 p.m. EST. They were particularly common in spring and summer, and reached maximum frequency in November and December. There was an average of 14.3 events each year, but a significant decreasing trend in terms of hail frequency and associated magnitude in the recent years has been identified. In turn, spatial models also established three main distribution patterns over the study area, which include the Sydney Metropolitan, coastal and pronounced

  11. Compressional and shear wave velocities in granular materials to 2.5 kilobars

    NASA Technical Reports Server (NTRS)

    Talwani, P.; Nur, A.; Kovach, R. L.

    1973-01-01

    The velocities of seismic compressional waves and, for the first time, shear wave velocities in silica sand, volcanic ash, and basalt powder were determined under hydrostatic confining pressures to 2.5 kb. Simultaneously, the porosity of these materials was obtained as a function of confining pressure. The presented results have important implications for the self-compaction hypothesis that has been postulated to explain the lunar near-surface seismic velocity variation.

  12. [Spatial-temporal variations of extractable organic matter in atmospheric PM10 and PM2.5 in Beijing].

    PubMed

    Dong, Xue-Ling; Liu, Da-Meng; Yuan, Yang-Sen; Che, Rui-Jun

    2009-02-15

    PM10 and PM2.5 samples were collected in parallel in different function zones of Beijing during four seasons of 2005. The pollution level, distribution characteristics of the extractable organic matter (EOM) and relationship between EOM (PM10) and EOM (PM2.5) were illustrated. The results show that: the annual mean concentrations of organic compound in PM10 and PM2.5 are 41.39 microg/m3 and 34.84 microg/m3, being 1.44 times and 1.26 times higher than Ming Tombs site. The concentrations of EOM in winter are 67.04 microg/m3 (PM10) and 64.64 microg/m3 (PM2.5), which are 1.15 and 1.82 times, 2.06 and 2.26 times, 4.53 and 6.26 times higher than that in spring, autumn, summer, respectively. Ratios of EOM in PM2.5 to that in PM10 in different seasons exceed 0.60. In different function zones the concentrations of EOM present industrial and commercial zones > living, traffic and contrast zones. The influence of EOM (PM2.5) on EOM (PM10) in different districts are various. The order of annual concentrations of organic compositions is non-hydrocarbons > asphaltenes > aromatics > saturated hydrocarbon. The seasonal emissions of pollution sources play an important role in seasonality of compositions of EOM. PMID:19402477

  13. Waste Management in Greater Dhaka City.

    ERIC Educational Resources Information Center

    Rahman, M. H.

    1993-01-01

    This study focuses on the environmental degradation of Greater Dhaka City (GDC) resulting from pollution created by the indiscriminate disposal of industrial wastes, open dumping of solid wastes, inadequate treatment and disposal of domestic sewage, and unplanned disposal of leachate from agricultural land. Measures to protect the GDC environment…

  14. Primary torsion of the greater omentum.

    PubMed

    Aoki, Y; Oka, S; Nakamura, M; Nakatsuka, H; Yamade, N; Maeda, Y

    1991-11-01

    A case with primary torsion of the greater omentum is reported. This pathological condition is an uncommon cause of acute abdominal emergency and it is very difficult even for general surgeons to differentiate this from other acute abdomen. The etiology remains unknown and the treatment of choice is resection of the affected organ. PMID:1820017

  15. Greater Capital Region Career Pathways Initiative

    ERIC Educational Resources Information Center

    Workforce Strategy Center, 2005

    2005-01-01

    This case study documents the activities of the Greater Capital Region Career Pathways Initiative (CPI), a partnership to develop regional, demand driven career pathways for the biotechnology sector in and around Albany, NY. This document is written for three primary audiences. First, it provides a report to the New York State Department of Labor…

  16. Comparisons of urban and rural PM10-2.5 and PM2.5 mass concentrations and semi-volatile fractions in northeastern Colorado

    NASA Astrophysics Data System (ADS)

    Clements, Nicholas; Hannigan, Michael P.; Miller, Shelly L.; Peel, Jennifer L.; Milford, Jana B.

    2016-06-01

    Coarse (PM10-2.5) and fine (PM2.5) particulate matter in the atmosphere adversely affect human health and influence climate. While PM2.5 is relatively well studied, less is known about the sources and fate of PM10-2.5. The Colorado Coarse Rural-Urban Sources and Health (CCRUSH) study measured PM10-2.5 and PM2.5 mass concentrations, as well as the fraction of semi-volatile material (SVM) in each size regime (SVM2.5, SVM10-2.5), from 2009 to early 2012 in Denver and comparatively rural Greeley, Colorado. Agricultural operations east of Greeley appear to have contributed to the peak PM10-2.5 concentrations there, but concentrations were generally lower in Greeley than in Denver. Traffic-influenced sites in Denver had PM10-2.5 concentrations that averaged from 14.6 to 19.7 µg m-3 and mean PM10-2.5 / PM10 ratios of 0.56 to 0.70, higher than at residential sites in Denver or Greeley. PM10-2.5 concentrations were more temporally variable than PM2.5 concentrations. Concentrations of the two pollutants were not correlated. Spatial correlations of daily averaged PM10-2.5 concentrations ranged from 0.59 to 0.62 for pairs of sites in Denver and from 0.47 to 0.70 between Denver and Greeley. Compared to PM10-2.5, concentrations of PM2.5 were more correlated across sites within Denver and less correlated between Denver and Greeley. PM10-2.5 concentrations were highest during the summer and early fall, while PM2.5 and SVM2.5 concentrations peaked in winter during periodic multi-day inversions. SVM10-2.5 concentrations were low at all sites. Diurnal peaks in PM10-2.5 and PM2.5 concentrations corresponded to morning and afternoon peaks of traffic activity, and were enhanced by boundary layer dynamics. SVM2.5 concentrations peaked around noon on both weekdays and weekends. PM10-2.5 concentrations at sites located near highways generally increased with wind speeds above about 3 m s-1. Little wind speed dependence was observed for the residential sites in Denver and Greeley. The mass

  17. 2,5-Dihydroxybenzoic acid: laser desorption/ionisation as a function of elevated temperature

    NASA Astrophysics Data System (ADS)

    Wallace, W. E.; Arnould, M. A.; Knochenmuss, R.

    2005-03-01

    The temperature dependence of laser desorption/ionization (LDI) ion yields has been measured for 2,5-dihydroxybenzoic acid (2,5-DHB) single crystals from room temperature to 160 °C using time-of-flight (TOF) mass spectrometry. A steep rise in ion production occurs at 90 °C, achieving a maximum at 120 °C, then decreases sharply to a minimum at 140 °C, and returns to a second maximum at 150 °C. Above 160 °C, useful information could not be obtained because of rapid volatilization of the sample into the vacuum. The overall trend in ion production, but not some of the details, is well described by a recent two-step theory of the laser desorption/ionization process, which takes into account the temperature-dependent effects of plume expansion. Measuring the background vacuum composition with a quadrupole mass spectrometer residual gas analyzer (RGA) showed an increase in thermal desorption of 2,5-DHB starting at 90 °C and maximizing at 130 °C. The increased neutral production by thermal desorption is believed to be the cause of the decrease in LDI ion production due to reduced pooling probabilities for laser-excited 2,5-DHB molecules. Thermal dehydration, condensation, and decarboxylation increase the volume of gas released at high temperatures which also serve to decrease LDI ion production at elevated temperatures. Lastly, to confirm the mass spectrometry results, the thermal desorption of 2,5-DHB single crystals under vacuum was measured using a quartz-crystal microbalance (QCM). The onset of desorption was found to occur at 90 °C and the maximum desorption rate was found at 135 °C.

  18. Scavenging of PM2.5 by precipitation and the effects of precipitation pattern changes on health risks related to PM2.5 in Tokyo, Japan.

    PubMed

    Ikeuchi, Hiroaki; Murakami, Michio; Watanabe, Satoshi

    2015-01-01

    Fine particulate matter (aerodynamic diameter<2.5 μm; PM2.5) poses risks to human health. While precipitation is the main process for decreasing ambient pollutant concentrations, scavenging of PM2.5 by precipitation remains to be investigated. Here we formulated the processes of PM2.5 scavenging by precipitation from observed PM2.5 concentrations ([PM2.5]) and precipitation intensities. Then we analyzed how changes in precipitation patterns would affect health risks related to PM2.5 on the basis of a Monte Carlo simulation. Tokyo, the capital of Japan, was selected as the target for this study because of its social significance. We found that [PM2.5] decreased significantly through scavenging of PM2.5 from the atmosphere by precipitation. In contrast, we found no significant correlation between reduction of [PM2.5] and precipitation intensity. Our model for estimating the reduction of PM2.5 and the Monte Carlo simulation showed good agreement with observations. Among various changes in potential precipitation patterns, changes in the arithmetic mean of the number of events and/or in precipitation duration were more influential on reduction of [PM2.5] than changes in their standard deviations. Health risks due to PM2.5 will increase with decreases in precipitation duration and occurrence.

  19. 2.5-D modeling in electromagnetic methods of geophysics

    NASA Astrophysics Data System (ADS)

    Tabarovsky, L. A.; Goldman, M. M.; Rabinovich, M. B.; Strack, K.-M.

    1996-10-01

    Understanding, using, or eliminating three-dimensional (3-D) effects in electromagnetic methods of geophysics are critical requirements. Numerous achievements in 3-D modeling sometimes give the impression that they are widely available today in geophysical practice. This is not necessarily true. Existing 3-D modeling packages prove that we know how to perform 3-D modeling. However, the computer resources and costs involved make the practical application of 3-D EM modeling in geophysical applications very limited. A practical compromise, or even alternative, is represented by 2.5-D modeling characterized by the use of a 3-D source in a 2-D medium. This combination allows one to mathematically describe the related boundary value problem as a sequence of independent two-dimensional problems. The typical technique leading to such a split formulation is Fourier analysis. That is why the individual terms of a split solution are often referred to as harmonics. Although each independent problem is two-dimensional, the algorithmic implementation of finite differences or integral equations for the higher harmonics has some specific features not present in the classical 2-D cases. In this paper, a hybrid scheme consisting of a combination of the finite difference technique with the integral equation approach for transient fields is described. Evaluation of algorithm accuracy is presented and a transient logging technique application is considered. The algorithm is fast and easily implemented on a personal computer

  20. Mechanism of charge transport in poly(2,5-dimethoxyaniline)

    NASA Astrophysics Data System (ADS)

    Singh, Rajiv K.; Kumar, Amit; Singh, Ramadhar

    2010-06-01

    Poly(2,5-dimethoxyaniline) (PDMA) has been synthesized by chemical oxidative polymerization technique using varying ratio of oxidants; ferric chloride (FeCl3) and ammonium persulfate [(NH4)2S2O8], in an inert atmosphere at low temperature ˜278 K. The synthesized samples of PDMA have been characterized by Fourier transform infrared spectroscopy, scanning electron microscopy and by measuring its dc conductivity (σdc). The temperature dependence of dc conductivity of PDMA samples has been examined in the wide temperature range 6-303 K. The analysis of dc conductivity data reveals that in the temperature range ˜100-303 K, the dc conductivity is predominantly governed by Mott's three-dimensional variable range hopping, however, below 100 K tunneling seems to dominate. Different Mott's parameters such as characteristic temperature (T0), density of states at the Fermi level [N(EF)], the average hopping distance (R ), and the average hopping energy (W) have been estimated for all the PDMA samples and are in good agreement with the values reported earlier for other conjugated polymers.

  1. Impact of Fine Particulate Matter (PM2.5) Exposure During Wildfires on Cardiovascular Health Outcomes

    PubMed Central

    Haikerwal, Anjali; Akram, Muhammad; Del Monaco, Anthony; Smith, Karen; Sim, Malcolm R; Meyer, Mick; Tonkin, Andrew M; Abramson, Michael J; Dennekamp, Martine

    2015-01-01

    Background Epidemiological studies investigating the role of fine particulate matter (PM2.5; aerodynamic diameter <2.5 μm) in triggering acute coronary events, including out-of-hospital cardiac arrests and ischemic heart disease (IHD), during wildfires have been inconclusive. Methods and Results We examined the associations of out-of-hospital cardiac arrests, IHD, acute myocardial infarction, and angina (hospital admissions and emergency department attendance) with PM2.5 concentrations during the 2006–2007 wildfires in Victoria, Australia, using a time-stratified case-crossover study design. Health data were obtained from comprehensive health-based administrative registries for the study period (December 2006 to January 2007). Modeled and validated air exposure data from wildfire smoke emissions (daily average PM2.5, temperature, relative humidity) were also estimated for this period. There were 457 out-of-hospital cardiac arrests, 2106 emergency department visits, and 3274 hospital admissions for IHD. After adjusting for temperature and relative humidity, an increase in interquartile range of 9.04 μg/m3 in PM2.5 over 2 days moving average (lag 0-1) was associated with a 6.98% (95% CI 1.03% to 13.29%) increase in risk of out-of-hospital cardiac arrests, with strong association shown by men (9.05%,95%CI 1.63% to 17.02%) and by older adults (aged ≥65 years) (7.25%, 95% CI 0.24% to 14.75%). Increase in risk was (2.07%, 95% CI 0.09% to 4.09%) for IHD-related emergency department attendance and (1.86%, 95% CI: 0.35% to 3.4%) for IHD-related hospital admissions at lag 2 days, with strong associations shown by women (3.21%, 95% CI 0.81% to 5.67%) and by older adults (2.41%, 95% CI 0.82% to 5.67%). Conclusion PM2.5 exposure was associated with increased risk of out-of-hospital cardiac arrests and IHD during the 2006–2007 wildfires in Victoria. This evidence indicates that PM2.5 may act as a triggering factor for acute coronary events during wildfire episodes

  2. Indoor PM2.5 in Santiago, Chile, spring 2012: Source apportionment and outdoor contributions

    NASA Astrophysics Data System (ADS)

    Barraza, Francisco; Jorquera, Héctor; Valdivia, Gonzalo; Montoya, Lupita D.

    2014-09-01

    Indoor and outdoor PM2.5 sampling campaigns were carried out at Santiago, Chile (6 million inhabitants, 33.5°S, 70.6°W) in spring 2012. A pair of samplers was placed inside each household studied and an additional pair of samplers was placed at a fixed outdoor location for measuring trace elements and elemental (EC) and organic carbon (OC) in Teflon and quartz filters, respectively. A total of 47 households in downtown Santiago were included in this study. Mean outdoor and indoor PM2.5 concentrations were 19.2 and 21.6 μg/m3, respectively. Indoor concentrations of PM2.5 were affected by socioeconomic status (p = 0.048) but no such evidence was found for PM2.5 species, except lead (p = 0.046). Estimated species infiltration factors were 0.70 (±0.19), 0.98 (±0.21), 0.80 (±0.12) and 0.80 (±0.03) for PM2.5, OC, EC and sulfur, respectively. Estimated household infiltration factors had a median of 0.75, mean of 0.78, standard deviation of 0.18 and interquartile range (IQR) 0.67-0.86. For the very first time, Positive Matrix Factorization (PMF3) was applied to an indoor PM2.5 chemical composition data set measured at Santiago. Source identification was carried out by inspection of key species and by comparison with published source profiles; six sources were identified. Three of them were outdoor contributions: motor vehicles with 5.6 (±0.7) μg/m3, street dust with 2.9 (±0.5) μg/m3 and secondary sulfates with 3.4 (±0.5) μg/m3. The indoor sources were: indoor dust with 1.6 (±0.3) μg/m3, cleaning and cooking with 2.3 (±0.3) μg/m3 and cooking and environmental tobacco smoke with 6.1 (±0.7) μg/m3. There is potential for further reducing PM2.5 population exposure in the short term -by improving ventilation of indoor air and controlling indoor sources - and in the long term - with filtration of outdoor air and household improvements to reduce air change rates.

  3. The distribution of PM10 and PM2.5 carbonaceous aerosol in Baotou, China

    NASA Astrophysics Data System (ADS)

    Zhou, Haijun; He, Jiang; Zhao, Boyi; Zhang, Lijun; Fan, Qingyun; Lü, Changwei; Dudagula; Liu, Tao; Yuan, Yinghui

    2016-09-01

    Particulate matter (PM), including PM10 and PM2.5, is one of the major impacts on air quality, visibility, climate change, earth radiation balance, and public health. Organic carbon (OC) and elemental carbon (EC) are the major components of PM. 804 samples (PM10 and PM2.5) were simultaneously collected from six urban sites covering 3 districts in Baotou, in January, April, September, and November 2014. As to a long-term study on the effects of carbonaceous aerosol, data were collected annually at Environmental Protection Agency of Baotou (EPB). The concentrations of PM10 and PM2.5, the spatial distribution and content of OC and EC, the relationship between OC and EC, and the formation of secondary organic carbon (SOC) have been investigated. The findings indicated that the concentrations of these particle matter are higher than that in US or European standards. The average concentrations of OC in PM10 and PM2.5 follow the order: January > November > April > September; and for EC in PM10 and PM2.5 follow the order: January > November > September > April. Affected by metrological factors, it was indicated that high wind speed and low relative humidity were beneficial for removal of OC and EC in January and November. Pearson correlations and cluster analysis on OC and EC concentrations in PM10 and PM2.5 with gaseous pollutants (SO2, NO2, and CO) suggested that OC shared the same emission sources with SO2 and CO from combustion, while EC's sources mainly came from vehicles exhaust and combustion which contributed to NO2 as well. The OC concentration is mainly primary in warm months, while it appears secondary in cold months in Baotou. There is a common characteristic among the cities with higher SOC in winter, wherever the coal combustion can lead to the severe pollution. This work is important for the construction of the database of OC and EC concentrations in PM10 and PM2.5 at spatial and time intervals, and it can provide scientific suggestion for similar PM

  4. Differences in allergic inflammatory responses between urban PM2.5 and fine particle derived from desert-dust in murine lungs.

    PubMed

    He, Miao; Ichinose, Takamichi; Kobayashi, Makoto; Arashidani, Keiichi; Yoshida, Seiichi; Nishikawa, Masataka; Takano, Hirohisa; Sun, Guifan; Shibamoto, Takayuki

    2016-04-15

    The biological and chemical natures of materials adsorbed onto fine particulate matter (PM2.5) vary by origin and passage routes. The exacerbating effects of the two samples-urban PM2.5 (U-PM2.5) collected during the hazy weather in a Chinese city and fine particles (ASD-PM2.5) collected during Asian sand dust (ASD) storm event days in Japan-on murine lung eosinophilia were compared to clarify the role of toxic materials in PM2.5. The amounts of β-glucan and mineral components were higher in ASD-PM2.5 than in U-PM2.5. On the other hand, organic chemicals, including polycyclic aromatic hydrocarbons (PAHs), were higher in U-PM2.5 than in ASD-PM2.5. When BALB/c mice were intratracheally instilled with U-PM2.5 and ASD-PM2.5 (total 0.4 mg/mouse) with or without ovalbumin (OVA), various biological effects were observed, including enhancement of eosinophil recruitment induced by OVA in the submucosa of the airway, goblet cell proliferation in the bronchial epithelium, synergic increase of OVA-induced eosinophil-relevant cytokines and a chemokine in bronchoalveolar lavage fluid, and increase of serum OVA-specific IgG1 and IgE. Data demonstrate that U-PM2.5 and ASD-PM2.5 induced allergic inflammatory changes and caused lung pathology. U-PM2.5 and ASD-PM2.5 increased F4/80(+) CD11b(+) cells, indicating that an influx of inflammatory and exudative macrophages in lung tissue had occurred. The ratio of CD206 positive F4/80(+) CD11b(+) cells (M2 macrophages) in lung tissue was higher in the OVA+ASD-PM2.5 treated mice than in the OVA+U-PM2.5 treated mice. These results suggest that the lung eosinophilia exacerbated by both PM2.5 is due to activation of a Th2-associated immune response along with induced M2 macrophages and the exacerbating effect is greater in microbial element (β-glucan)-rich ASD-PM2.5 than in organic chemical-rich U-PM2.5. PMID:26917405

  5. Bidirectional reflectance measurement of zinc oxide in 0.25 to 2.5 microns spectrum

    NASA Technical Reports Server (NTRS)

    Scott, R. L., Jr.

    1974-01-01

    An experimental apparatus was designed and used to measure the bidirectional reflectance of zinc oxide in the spectrum 0.25 to 2.5 microns. The nonspecular reflectance is essentially Lambert for wavelengths above 0.40 microns with the most deviation occuring for large source zenith angles. Below 0.400 microns the nonspecular reflectance is greater than Lambert in all directions and is greatest in the forward and backscatter directions. The ratio of the specular component to the nonspecular component at a zenith of 0 degrees was found to increase with source zenith and wavelength for wavelengths above 0.400 microns. Below 0.400 microns this ratio increases as wavelengths decrease. The variation of bidirectional reflectance with wavelength was found to have the characteristics absorption for Zn0 for wavelength below 0.400 microns.

  6. Modeling the spatio-temporal heterogeneity in the PM10-PM2.5 relationship

    NASA Astrophysics Data System (ADS)

    Chu, Hone-Jay; Huang, Bo; Lin, Chuan-Yao

    2015-02-01

    This paper explores the spatio-temporal patterns of particulate matter (PM) in Taiwan based on a series of methods. Using fuzzy c-means clustering first, the spatial heterogeneity (six clusters) in the PM data collected between 2005 and 2009 in Taiwan are identified and the industrial and urban areas of Taiwan (southwestern, west central, northwestern, and northern Taiwan) are found to have high PM concentrations. The PM10-PM2.5 relationship is then modeled with global ordinary least squares regression, geographically weighted regression (GWR), and geographically and temporally weighted regression (GTWR). The GTWR and GWR produce consistent results; however, GTWR provides more detailed information of spatio-temporal variations of the PM10-PM2.5 relationship. The results also show that GTWR provides a relatively high goodness of fit and sufficient space-time explanatory power. In particular, the PM2.5 or PM10 varies with time and space, depending on weather conditions and the spatial distribution of land use and emission patterns in local areas. Such information can be used to determine patterns of spatio-temporal heterogeneity in PM that will allow the control of pollutants and the reduction of public exposure.

  7. Calibrating a ground-based backscatter lidar for continuous measurements of PM2.5

    NASA Astrophysics Data System (ADS)

    Pesch, Markus; Oderbolz, Daniel

    2007-10-01

    One of the main issues of atmospheric research and air quality control is the reduction of harmful particulate matter (PM) in the atmosphere. Small particles can enter the human airways and cause serious health problems such as COPD (Chronic Obstructive Pulmonary Disease), asthma or even lung cancer. Recently, interest has shifted from PM10 to finer fractions of particulate matter, e.g. PM2.5, because the health impact of finer particles is considered to be more severe. Up to now measurements of particulate matter were carried out mainly at ground level. However important atmospheric processes, i.e. particle formation, transport and vertical mixing processes, take place predominantly at higher altitudes in the planetary boundary layer. Lidar in principle provides the ability to observe these processes where they occur. The new method outlined in this paper demonstrates the use of a small sized and quite inexpensive lidar in stand-alone operation to investigate transport processes of particulate matter, and PM2.5 in particular. Continuous measurements of PM2.5 as a reference are gained with a conventional in-situ monitor, installed on a tower at an altitude of 325 m in the North of Berlin (Frohnauer Turm). These PM2.5 measurements will be compared with backscatter Lidar data (1064 nm) taken from approx. 60 m over ground up to an altitude of 15 km with a spatial resolution of 15 m. The vertical backscatter profiles at 325 m will be correlated to the concentrations obtained by the PM2,5 monitor on the tower. Both measurements have a time resolution of 180 s to observe also processes that take place at short time scales. The objective is to gain correlation functions for estimating PM2.5 concentrations from backscatter Lidar data. Such a calibrated Lidar system is a valuable instrument for environmental agencies and atmospheric research groups to observe and investigate causes of high level PM concentrations. First results show a reasonably good linear correlation

  8. AO Spectroscopy of Charon Between 1.4-2.5 (mu)m

    NASA Astrophysics Data System (ADS)

    Cook, Jason C.; Desch, Steve; Wyckoff, Susan; Geballe, Tom; Trujillo, Chad

    2005-08-01

    At the outer bounds of the solar system, Pluto and Charon represent the largest of the Kuiper Belt Objects (KBOs). Spectroscopic observations of several recently discovered large KBOs (600 ≲ r ≲ 1200 km) show surfaces similar to Charon suggesting a link between these objects. To better understand the physical properties of Pluto and Charon, and to provide insights into their origin and evolution in the context of other outer solar system objects, we propose the first spectroscopic program to study the surface of Charon using the AO instrument on Gemini North. The surface of Charon is mainly covered by crystalline H_2O ice, shown by the 1.65 (micron) feature. Grundy et al. (1999) showed this feature is highly temperature sensitive. Based on the best pure Charon spectra, the surface temperature was measured at 60+/-20 K (Buie & Grundy, 2000) however, the greater spectral resolution of NIRI- Altair will measure the temperature to within 2-5 K, if not better. Additional cosmochemically abundant ices expected in the 1.4-2.5 (micron) region include CO_2, NH_3 and CH_4 (Roush, 1994, Brown & Calvin, 2000), but have eluded detection to date due to low resolution and poor signal-to-noise (SNR). Rotationally resolved spectra of Charon using Altair-NIRI will be obtained to search for the presence and distribution of these ices. For those species not detected, significant limits will be determined.

  9. Environmental planning and management in Greater Johannesburg.

    PubMed

    Von Schirnding, Y E

    1996-03-01

    This article describes the actions among urban environmental, management, and development planners in Greater Johannesburg, South Africa. Initiatives, such as the Healthy Cities Project and Model Communities, are being integrated into an environmental management and development approach that attains the goals of Agenda 21. Greater Johannesburg has housing shortages and homelessness. Priority needs include the areas of housing, water, electricity, public transportation, and sanitation. Clean water and air are inequitably distributed. Other key environmental problems include illegal dumping, inadequate waste disposal, poor environmental hygiene in overcrowded inner city areas, lack of open spaces, flooding, and water scarcities. The newly formed metropolitan authority offers opportunities to improve coordination and integration of environmental problems. Stakeholders from government at all levels, politicians, nongovernmental organizations, and the business sector formed an intersectoral, interdepartmental environment management committee in 1995. Stakeholders will integrate Agenda 21 within broader urban development plans and processes. The executive committee and the full council approved a set of guiding principles on environmental policy and an administrative framework for management. Four workshops were held to ensure a participatory consultation process in 1995. The WHO Collaborating Center for Urban Health will be used to facilitate the work of the Greater Johannesburg Metropolitan Council. Changes are being made in the way local governments work.

  10. Greater trochanter apophysitis in the adolescent athlete.

    PubMed

    Young, Simon W; Safran, Marc R

    2015-05-01

    Lower limb traction apophysitis is common in young athletes, occurring at sites such as the tibial tubercle (Osgood-Schlatter disease) and distal patella (Sinding-Larsen-Johansson disease). Around the hip, iliac apophysitis is well recognized, but no cases of greater trochanter apophysitis have previously been reported. We describe the case of a 15-year-old male basketball player with a 2-month history of the right hip pain and significant functional limitation. X-rays revealed widening of the greater trochanter apophysis with subchondral sclerosis, consistent with a diagnosis of traction apophysitis. The patient was treated with a period of relative rest and anti-inflammatory medication. He gradually returned to full athletic activity, including basketball, without recurrence of pain or limitation. We describe the first reported case of traction apophysitis of the greater trochanter. The unique muscular anatomy of this apophysis with balanced forces explains the rarity of this condition. If encountered, rest and activity modification is the recommended treatment.

  11. Lagged PM2.5 effects in mortality time series: Critical impact of covariate model

    EPA Science Inventory

    The two most common approaches to modeling the effects of air pollution on mortality are the Harvard and the Johns Hopkins (NMMAPS) approaches. These two approaches, which use different sets of covariates, result in dissimilar estimates of the effect of lagged fine particulate ma...

  12. INTEGRATED AND REAL-TIME DIFFUSION DENUDER SAMPLE FOR PM2.5. (R825367)

    EPA Science Inventory

    Abstract

    Particulate matter (PM) is a complex mixture of stable condensed phases, adsorbed or dissolved gases, and semi-volatile materials, i.e. compounds that transfer between the gas and condensed phases. Fine particles in both rural and urban environments contain su...

  13. Sandia Advanced MEMS Design Tools, Version 2.2.5

    SciTech Connect

    Yarberry, Victor; Allen, James; Lantz, Jeffery; Priddy, Brian; & Westling, Belinda

    2010-01-19

    The Sandia National Laboratories Advanced MEMS Design Tools, Version 2.2.5, is a collection of menus, prototype drawings, and executables that provide significant productivity enhancements when using AutoCAD to design MEMS components. This release is designed for AutoCAD 2000i, 2002, or 2004 and is supported under Windows NT 4.0, Windows 2000, or XP. SUMMiT V (Sandia Ultra planar Multi level MEMS Technology) is a 5 level surface micromachine fabrication technology, which customers internal and external to Sandia can access to fabricate prototype MEMS devices. This CD contains an integrated set of electronic files that: a) Describe the SUMMiT V fabrication process b) Facilitate the process of designing MEMS with the SUMMiT process (prototype file, Design Rule Checker, Standard Parts Library) New features in this version: AutoCAD 2004 support has been added. SafeExplode ? a new feature that explodes blocks without affecting polylines (avoids exploding polylines into objects that are ignored by the DRC and Visualization tools). Layer control menu ? a pull-down menu for selecting layers to isolate, freeze, or thaw. Updated tools: A check has been added to catch invalid block names. DRC features: Added username/password validation, added a method to update the user?s password. SNL_DRC_WIDTH ? a value to control the width of the DRC error lines. SNL_BIAS_VALUE ? a value use to offset selected geometry SNL_PROCESS_NAME ? a value to specify the process name Documentation changes: The documentation has been updated to include the new features. While there exist some files on the CD that are used in conjunction with software package AutoCAD, these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.

  14. Sandia Advanced MEMS Design Tools, Version 2.2.5

    2010-01-19

    The Sandia National Laboratories Advanced MEMS Design Tools, Version 2.2.5, is a collection of menus, prototype drawings, and executables that provide significant productivity enhancements when using AutoCAD to design MEMS components. This release is designed for AutoCAD 2000i, 2002, or 2004 and is supported under Windows NT 4.0, Windows 2000, or XP. SUMMiT V (Sandia Ultra planar Multi level MEMS Technology) is a 5 level surface micromachine fabrication technology, which customers internal and external tomore » Sandia can access to fabricate prototype MEMS devices. This CD contains an integrated set of electronic files that: a) Describe the SUMMiT V fabrication process b) Facilitate the process of designing MEMS with the SUMMiT process (prototype file, Design Rule Checker, Standard Parts Library) New features in this version: AutoCAD 2004 support has been added. SafeExplode ? a new feature that explodes blocks without affecting polylines (avoids exploding polylines into objects that are ignored by the DRC and Visualization tools). Layer control menu ? a pull-down menu for selecting layers to isolate, freeze, or thaw. Updated tools: A check has been added to catch invalid block names. DRC features: Added username/password validation, added a method to update the user?s password. SNL_DRC_WIDTH ? a value to control the width of the DRC error lines. SNL_BIAS_VALUE ? a value use to offset selected geometry SNL_PROCESS_NAME ? a value to specify the process name Documentation changes: The documentation has been updated to include the new features. While there exist some files on the CD that are used in conjunction with software package AutoCAD, these files are not intended for use independent of the CD. Note that the customer must purchase his/her own copy of AutoCAD to use with these files.« less

  15. Meteorological Modes of Variability for Fine Particulate Matter (PM2.5) Air Quality in the United States: Implications for PM2.5 Sensitivity to Climate Change

    EPA Science Inventory

    We applied a multiple linear regression model to understand the relationships of PM2.5 with meteorological variables in the contiguous US and from there to infer the sensitivity of PM2.5 to climate change. We used 2004-2008 PM2.5 observations fro...

  16. Time?

    NASA Astrophysics Data System (ADS)

    Amoroso, Richard L.

    2013-09-01

    The concept of time in the `clockwork' Newtonian world was irrelevant; and has generally been ignored until recently by several generations of physicists since the implementation of quantum mechanics. We will set aside the utility of time as a property relating to physical calculations of events relating to a metrics line element or as an aspect of the transformation of a particles motion/interaction in a coordinate system or in relation to thermodynamics etc., i.e. we will discard all the usual uses of time as a concept used to circularly define physical parameters in terms of other physical parameters; concentrating instead on time as an aspect of the fundamental cosmic topology of our virtual reality especially as it inseparably relates to the nature and role of the observer in natural science.

  17. PM2.5 Population Exposure in New Delhi Using a Probabilistic Simulation Framework.

    PubMed

    Saraswat, Arvind; Kandlikar, Milind; Brauer, Michael; Srivastava, Arun

    2016-03-15

    This paper presents a Geographical Information System (GIS) based probabilistic simulation framework to estimate PM2.5 population exposure in New Delhi, India. The framework integrates PM2.5 output from spatiotemporal LUR models and trip distribution data using a Gravity model based on zonal data for population, employment and enrollment in educational institutions. Time-activity patterns were derived from a survey of randomly sampled individuals (n = 1012) and in-vehicle exposure was estimated using microenvironmental monitoring data based on field measurements. We simulated population exposure for three different scenarios to capture stay-at-home populations (Scenario 1), working population exposed to near-road concentrations during commutes (Scenario 2), and the working population exposed to on-road concentrations during commutes (Scenario 3). Simulated annual average levels of PM2.5 exposure across the entire city were very high, and particularly severe in the winter months: ∼200 μg m(-3) in November, roughly four times higher compared to the lower levels in the monsoon season. Mean annual exposures ranged from 109 μg m(-3) (IQR: 97-120 μg m(-3)) for Scenario 1, to 121 μg m(-3) (IQR: 110-131 μg m(-3)), and 125 μg m(-3) (IQR: 114-136 μ gm(-3)) for Scenarios 2 and 3 respectively. Ignoring the effects of mobility causes the average annual PM2.5 population exposure to be underestimated by only 11%. PMID:26885573

  18. Physical characterization of a new composition of oxidized zirconium-2.5 wt% niobium produced using a two step process for biomedical applications

    NASA Astrophysics Data System (ADS)

    Pawar, V.; Weaver, C.; Jani, S.

    2011-05-01

    Zirconium and particularly Zr-2.5 wt%Nb (Zr2.5Nb) alloy are useful for engineering bearing applications because they can be oxidized in air to form a hard surface ceramic. Oxidized zirconium (OxZr) due to its abrasion resistant ceramic surface and biocompatible substrate alloy has been used as a bearing surface in total joint arthroplasty for several years. OxZr is characterized by hard zirconium oxide (oxide) formed on Zr2.5Nb using one step thermal oxidation carried out in air. Because the oxide is only at the surface, the bulk material behaves like a metal, with high toughness. The oxide, furthermore, exhibits high adhesion to the substrate because of an oxygen-rich diffusion hardened zone (DHZ) interposing between the oxide and the substrate. In this study, we demonstrate a two step process that forms a thicker DHZ and thus increased depth of hardening than that can be obtained using a one step oxidation process. The first step is thermal oxidation in air and the second step is a heat treatment in vacuum. The second step drives oxygen from the oxide formed in the first step deeper into the substrate to form a thicker DHZ. During the process only a portion of the oxide is dissolved. This new composition (DHOxZr) has approximately 4-6 μm oxide similar to that of OxZr. The nano-hardness of the oxide is similar but the DHZ is approximately 10 times thicker. The stoichiometry of the oxide is similar and a secondary phase rich in oxygen is present through the entire thickness. Due to the increased depth of hardening, the critical load required for the onset of oxide cracking is approximately 1.6 times more than that of the oxide of OxZr. This new composition has a potential to be used as a bearing surface in applications where greater depth of hardening is required.

  19. An LUR/BME Framework to Estimate PM2.5 Explained by on Road Mobile and Stationary Sources

    PubMed Central

    2015-01-01

    Knowledge of particulate matter concentrations <2.5 μm in diameter (PM2.5) across the United States is limited due to sparse monitoring across space and time. Epidemiological studies need accurate exposure estimates in order to properly investigate potential morbidity and mortality. Previous works have used geostatistics and land use regression (LUR) separately to quantify exposure. This work combines both methods by incorporating a large area variability LUR model that accounts for on road mobile emissions and stationary source emissions along with data that take into account incompleteness of PM2.5 monitors into the modern geostatistical Bayesian Maximum Entropy (BME) framework to estimate PM2.5 across the United States from 1999 to 2009. A cross-validation was done to determine the improvement of the estimate due to the LUR incorporation into BME. These results were applied to known diseases to determine predicted mortality coming from total PM2.5 as well as PM2.5 explained by major contributing sources. This method showed a mean squared error reduction of over 21.89% oversimple kriging. PM2.5 explained by on road mobile emissions and stationary emissions contributed to nearly 568 090 and 306 316 deaths, respectively, across the United States from 1999 to 2007. PMID:24387222

  20. An LUR/BME framework to estimate PM2.5 explained by on road mobile and stationary sources.

    PubMed

    Reyes, Jeanette M; Serre, Marc L

    2014-01-01

    Knowledge of particulate matter concentrations <2.5 μm in diameter (PM2.5) across the United States is limited due to sparse monitoring across space and time. Epidemiological studies need accurate exposure estimates in order to properly investigate potential morbidity and mortality. Previous works have used geostatistics and land use regression (LUR) separately to quantify exposure. This work combines both methods by incorporating a large area variability LUR model that accounts for on road mobile emissions and stationary source emissions along with data that take into account incompleteness of PM2.5 monitors into the modern geostatistical Bayesian Maximum Entropy (BME) framework to estimate PM2.5 across the United States from 1999 to 2009. A cross-validation was done to determine the improvement of the estimate due to the LUR incorporation into BME. These results were applied to known diseases to determine predicted mortality coming from total PM2.5 as well as PM2.5 explained by major contributing sources. This method showed a mean squared error reduction of over 21.89% oversimple kriging. PM2.5 explained by on road mobile emissions and stationary emissions contributed to nearly 568,090 and 306,316 deaths, respectively, across the United States from 1999 to 2007.

  1. 2,5-hexanedione altered the degradation of low-molecular-weight neurofilament in rat nerve tissues.

    PubMed

    Song, Fuyong; Zhang, Qingguo; Kou, Ruirui; Zou, Chaoshuang; Gao, Yuan; Xie, Keqin

    2012-12-01

    Occupational exposure to n-hexane produces a central-peripheral distal axonopathy, which is characterized by giant axonal swellings filled with neurofilaments (NFs). To investigate the change of NFs degradation and their possible role in n-hexane neuropathy, adult male Wistar rats were administered intraperitoneally at a dosage of 400 mg/kg/day 2,5-hexanedione (2,5-HD) for 4 weeks. The time course of low-molecular-weight neurofilament (NF-L) degradation and autophagy-related protein in rat sciatic nerves and spinal cords was determined by Western blotting. The results demonstrated that the administration of 2,5-HD inhibited NF-L degradation to an undetectable level in sciatic nerves. Furthermore, a significant reduction of NF-L degradation in spinal cords was observed in the early stage of 2,5-HD exposure. In the meantime, 2,5-HD significantly decreased the level of Beclin-1, a key autophagy-regulated protein in sciatic nerves of rats while increased the level of P62, a selective substrate of autophagy degrading pathway, which indicated a dysfunctional autophagy in rat nerve tissues. Collectively, our findings suggested that the inhibition of autophagy by 2,5-HD might be responsible for the reduction of NF-L degradation in rat sciatic nerves, and involved in the pathogenesis of 2,5-HD-induced axonopathy.

  2. 2.5D complex resistivity modeling and inversion using unstructured grids

    NASA Astrophysics Data System (ADS)

    Xu, Kaijun; Sun, Jie

    2016-04-01

    The characteristic of complex resistivity on rock and ore has been recognized by people for a long time. Generally we have used the Cole-Cole Model(CCM) to describe complex resistivity. It has been proved that the electrical anomaly of geologic body can be quantitative estimated by CCM parameters such as direct resistivity(ρ0), chargeability(m), time constant(τ) and frequency dependence(c). Thus it is very important to obtain the complex parameters of geologic body. It is difficult to approximate complex structures and terrain using traditional rectangular grid. In order to enhance the numerical accuracy and rationality of modeling and inversion, we use an adaptive finite-element algorithm for forward modeling of the frequency-domain 2.5D complex resistivity and implement the conjugate gradient algorithm in the inversion of 2.5D complex resistivity. An adaptive finite element method is applied for solving the 2.5D complex resistivity forward modeling of horizontal electric dipole source. First of all, the CCM is introduced into the Maxwell's equations to calculate the complex resistivity electromagnetic fields. Next, the pseudo delta function is used to distribute electric dipole source. Then the electromagnetic fields can be expressed in terms of the primary fields caused by layered structure and the secondary fields caused by inhomogeneities anomalous conductivity. At last, we calculated the electromagnetic fields response of complex geoelectric structures such as anticline, syncline, fault. The modeling results show that adaptive finite-element methods can automatically improve mesh generation and simulate complex geoelectric models using unstructured grids. The 2.5D complex resistivity invertion is implemented based the conjugate gradient algorithm.The conjugate gradient algorithm doesn't need to compute the sensitivity matrix but directly computes the sensitivity matrix or its transpose multiplying vector. In addition, the inversion target zones are

  3. Greater Sage-Grouse National Research Strategy

    USGS Publications Warehouse

    Hanser, Steven E.; Manier, Daniel J.

    2013-01-01

    The condition of the sagebrush ecosystem has been declining in the Western United States, and greater sage-grouse (Centrocercus urophasianus), a sagebrush-obligate species, has experienced concurrent decreases in distribution and population numbers. This has prompted substantial research and management over the past two decades to improve the understanding of sage-grouse and its habitats and to address the observed decreases in distribution and population numbers. The amount of research and management has increased as the year 2015 approaches, which is when the U.S. Fish and Wildlife Service (FWS) is expected to make a final decision about whether or not to protect the species under the Endangered Species Act. In 2012, the Sage-Grouse Executive Oversight Committee (EOC) of the Western Association of Fish and Wildlife Agencies (WAFWA) requested that the U.S. Geological Survey (USGS) lead the development of a Greater Sage-Grouse National Research Strategy (hereafter Research Strategy). This request was motivated by a practical need to systematically connect existing research and conservation plans with persisting or emerging information needs. Managers and researchers also wanted to reduce redundancy and help focus limited funds on the highest priority research and management issues. The USGS undertook the development of this Research Strategy, which addresses information and science relating to the greater sage-grouse and its habitat across portions of 11 Western States. This Research Strategy provides an outline of important research topics to ensure that science information gaps are identified and documented in a comprehensive manner. Further, by identifying priority topics and critical information needed for planning, research, and resource management, it provides a structure to help coordinate members of an expansive research and management community in their efforts to conduct priority research.

  4. Determination of 2-5A synthetase and 2-5A phosphodiesterase in neuroblastoma cells by analytical capillary isotachophoresis: effects of cytokines and comparison with radioenzymatic methods.

    PubMed

    Bruchelt, G; Büdenbender, M; Schmidt, K H; Birk, A; Treuner, J; Niethammer, D

    1994-01-01

    2-5A Synthetase and 2-5A phosphodiesterase were determined by analytical capillary isotachophoresis in comparison to radioenzymatic methods. By means of isotachophoretic analysis, a frequently used radioenzymatic 2-5A synthetase assay was optimized and the results of both assays were compared. Using the isotachophoretic assay the influence of interferon-related cytokines (tumor necrosis factor-alpha and interleukin-2) on 2-5A synthetase induction in neuroblastoma cells was estimated. In contrast to mononuclear blood cells, the tumor necrosis factor induced 2-5A synthetase in these cells. 2-5A Phosphodiesterase was determined using an isotachophoretic assay and a radioenzymatic method. Degradation of A2'p5'A2'p5'A (trimeric form of 2-5A core) was measured by isotachophoresis whereas degradation of a mixture of phosphorus-32 labeled 2-5A cores was registered by radioenzymatic assay. Activity of 2-5A phosphodiesterase was only insignificantly enhanced by interferon in mononuclear blood and neuroblastoma cells. In contrast to the radioenzymatic assays, an accurate determination of 2-5A synthetase as well as of 2-5A phosphodiesterase is possible using the isotachophoretic method because the reactions are followed by measuring the substrates ATP and A2'p5'A2'p5'A, respectively.

  5. Hospital design to support greater operating efficiency.

    PubMed

    Skaggs, R L

    1984-12-01

    With the new imperative on cost containment and particular emphasis on prospective payment, hospital design must support greater productivity. It is incumbent on architects and engineers to reduce construction costs; but more importantly, to design facilities that improve personnel productivity. Several approaches to designing for efficiency are discussed including improving the development process; systems building, ease of maintenance, and conserving energy; developing the model hospital; minimizing travel throughout the hospital; centralization vs. decentralization; automating support systems; designing for growth and change; analyzing workflow; utilizing swing space; and emphasizing consumer centered care.

  6. Interspecific hybridization between greater kudu and nyala.

    PubMed

    Dalton, Desiré L; Tordiffe, Adrian; Luther, Ilse; Duran, Assumpta; van Wyk, Anna M; Brettschneider, Helene; Oosthuizen, Almero; Modiba, Catherine; Kotzé, Antoinette

    2014-06-01

    Hybridization of wildlife species, even in the absence of introgression, is of concern due to wasted reproductive effort and a reduction in productivity. In this study we detail an accidental mating between a female nyala (Tragelaphus angasii) and a male greater kudu (T. strepsiceros). The hybrid was phenotypically nyala and was identified as such based on mitochondrial DNA. Further genetic analysis based on nine microsatellite markers, chromosome number and chromosome morphology however, confirmed its status as an F1 hybrid. Results obtained from a reproductive potential assessment indicated that this animal does not have the potential to breed successfully and can be considered as sterile.

  7. Greater auricular nerve masquerading as lymph node

    PubMed Central

    Saxena, Shilpi; Deb, Prabal; Nijhawan, Vijay Shrawan; Kharayat, Veena; Verma, Rajesh

    2015-01-01

    Hansen's disease is on the verge of being eliminated from India and often missed by clinicians due to low index of suspicion. We present an unusual case in which greater auricular nerve thickening masqueraded as enlarged lymph node in the neck. The patient was referred for fine needle aspiration cytology, which revealed epithelioid cell granulomas suggestive of Hansen's disease. Further clinical examination and investigations including the skin biopsy confirmed the disease, highlighting the role of pathologist in the management of such unusual presentation of a common disease. PMID:26229249

  8. Detection and quantitation of 2,5-diketopiperazines in wheat sourdough and bread.

    PubMed

    Ryan, Liam A M; Dal Bello, Fabio; Arendt, Elke K; Koehler, Peter

    2009-10-28

    Liquid chromatography mass spectrometry (LC-MS) was used to quantify the levels of the 2,5-diketopiperazines cis-cyclo(L-Leu-L-Pro) and cis-cyclo(L-Phe-L-Pro) in acidified dough and bread. Dough acidification led to a significant increase in the level of cis-cyclo(L-Leu-L-Pro) and cis-cyclo(L-Phe-L-Pro) over 48 h compared to a nonacidified dough. However, no differences were found between chemically (mix of lactic and acetic acid in the presence of antibiotics) and biologically acidified doughs. On examination of the levels of cis-cyclo(L-Leu-L-Pro) and cis-cyclo(L-Phe-L-Pro) in bread crumb and crust, it was found that temperature is the main causative agent of 2,5-diketopiperazine formation during the baking process. Bread crumb and crust contained almost 100 and 2000 times respectively the levels found in dough prior to baking. cis-Cyclo(L-Leu-L-Pro) and cis-cyclo(L-Phe-L-Pro) were also found to be at sensorally active levels in bread crust, however both 2,5-diketopiperazines were found to be below the minimum inhibitory concentration for antifungal activity in bread.

  9. Sequential Measurement of Intermodal Variability in Public Transportation PM2.5 and CO Exposure Concentrations.

    PubMed

    Che, W W; Frey, H Christopher; Lau, Alexis K H

    2016-08-16

    A sequential measurement method is demonstrated for quantifying the variability in exposure concentration during public transportation. This method was applied in Hong Kong by measuring PM2.5 and CO concentrations along a route connecting 13 transportation-related microenvironments within 3-4 h. The study design takes into account ventilation, proximity to local sources, area-wide air quality, and meteorological conditions. Portable instruments were compacted into a backpack to facilitate measurement under crowded transportation conditions and to quantify personal exposure by sampling at nose level. The route included stops next to three roadside monitors to enable comparison of fixed site and exposure concentrations. PM2.5 exposure concentrations were correlated with the roadside monitors, despite differences in averaging time, detection method, and sampling location. Although highly correlated in temporal trend, PM2.5 concentrations varied significantly among microenvironments, with mean concentration ratios versus roadside monitor ranging from 0.5 for MTR train to 1.3 for bus terminal. Measured inter-run variability provides insight regarding the sample size needed to discriminate between microenvironments with increased statistical significance. The study results illustrate the utility of sequential measurement of microenvironments and policy-relevant insights for exposure mitigation and management.

  10. Environmentally Persistent Free Radicals and Their Lifetimes in PM2.5

    PubMed Central

    Gehling, William; Dellinger, Barry

    2015-01-01

    For the first time, an expansive study into the concentration and extended decay behavior of environmentally persistent free radicals in PM2.5 was performed. Results from this study revealed three types of radical decay—a fast decay, slow decay, and no decay—following one of four decay patterns: a relatively fast decay exhibiting a 1/e lifetime of 1–21 days accompanied by a slow decay with a 1/e lifetime of 21–5028 days (47% of samples); a single slow decay including a 1/e lifetime of 4–2083 days (24% of samples); no decay (18% of samples); and a relatively fast decay displaying an average 1/e lifetime of 0.25–21 days followed by no decay (11% of samples). Phenol correlated well with the initial radical concentration and fast decay rate. Other correlations for common atmospheric pollutants (ozone, NOx, SO2, etc.) as well as meteorological conditions suggested photochemical processes impact the initial radical concentration and fast decay rate. The radical signal in PM2.5 was remarkably similar to semiquinones in cigarette smoke. Accordingly, radicals inhaled from PM2.5 were related to the radicals inhaled from smoking cigarettes, expressed as the number of equivalent cigarettes smoked. This calculated to 0.4–0.9 cigarettes per day for nonextreme air quality in the United States. PMID:23844657

  11. Sequential Measurement of Intermodal Variability in Public Transportation PM2.5 and CO Exposure Concentrations.

    PubMed

    Che, W W; Frey, H Christopher; Lau, Alexis K H

    2016-08-16

    A sequential measurement method is demonstrated for quantifying the variability in exposure concentration during public transportation. This method was applied in Hong Kong by measuring PM2.5 and CO concentrations along a route connecting 13 transportation-related microenvironments within 3-4 h. The study design takes into account ventilation, proximity to local sources, area-wide air quality, and meteorological conditions. Portable instruments were compacted into a backpack to facilitate measurement under crowded transportation conditions and to quantify personal exposure by sampling at nose level. The route included stops next to three roadside monitors to enable comparison of fixed site and exposure concentrations. PM2.5 exposure concentrations were correlated with the roadside monitors, despite differences in averaging time, detection method, and sampling location. Although highly correlated in temporal trend, PM2.5 concentrations varied significantly among microenvironments, with mean concentration ratios versus roadside monitor ranging from 0.5 for MTR train to 1.3 for bus terminal. Measured inter-run variability provides insight regarding the sample size needed to discriminate between microenvironments with increased statistical significance. The study results illustrate the utility of sequential measurement of microenvironments and policy-relevant insights for exposure mitigation and management. PMID:27182735

  12. Exposure to PM2.5 and PAHs from the Tong Liang, China epidemiological study.

    PubMed

    Chow, Judith C; Watson, John G; Chen, Lung-Wen Antony; Ho, Steven Sai Hang; Koracin, Darko; Zielinska, Barbara; Tang, Deliang; Perera, Frederica; Cao, Junji; Lee, S C

    2006-01-01

    Chemically speciated PM2.5 and particle-bound polycyclic aromatic hydrocarbon (PAH) measurements were made at three sites near urban Tong Liang, Chongqing, a Chinese inland city where coal combustion is used for electricity generation and residential purposes outside of the central city. Ambient sampling was based on 72-hr averages between 3/2/2002 and 2/26/2003. Elevated PM2.5 and PAH concentrations were observed at all three sites, with the highest concentrations found in winter and the lowest in summer. This reflects a coupling effect of source variability and meteorological conditions. The PM2.5 mass estimated from sulfate, nitrate, ammonium, organics, elemental carbon, crustal material, and salt corresponded with the annual average gravimetric mass within +/-10%. Carbonaceous aerosol was the dominant species, while positive correlations between organic carbon and trace elements (e.g., As, Se, Br, Pb, and Zn) were consistent with coal-burning and motor vehicle contributions. Ambient particle-bound PAHs of molecular weight 168-266 were enriched by 1.5 to 3.5 times during the coal-fired power plant operational period. However, further investigation is needed to determine the relative contribution from residential and utility coal combustion and vehicular activities. PMID:16779929

  13. Assessment of PM2.5 concentrations on Human Health: A case study of Delhi, India

    NASA Astrophysics Data System (ADS)

    Goyal, P.; Mishra, D.

    2015-12-01

    Connection of air quality with human health is well established in the literature. However the associated health risks due to fine particulate matter (PM2.5) concentration is not well known in India, while the assigned mean threshold values are 60 μg/m3 for 24-hour period and 40 μg/m3 for annual period. Both are considered safe concentration limits regarding human health effects. However, the daily and annually concentrations of PM2.5 were observed more than three times of NAAQS in the present study for a year. This study relates the incessant exposure to significant levels of PM2.5 to deleterious health effects, such as heart and lung diseases. The relation between environmental air quality and human health has been studied through different parameters e.g., hazard quotient (HQ), lifetime incremental cancer risk (LICR), and individual risk for different groups of ages in Delhi, the capital city of India. These analysis lead to additional insights into health disparities and may suggest that more rigorous strategies. This may be application to other urban areas across the nation. In this study, we propose to quantify such impacts through estimation of different health risk factors.

  14. Six lessons learned for greater success.

    PubMed

    Leander, W J

    1993-01-01

    These six lessons learned for greater success with your Patient Focused communications can help keep your cultural change process in sync with your operational change process. Of course, there are other key elements of the former, including: formal Patient Focused educational programs; restructured Human Resources "systems" (e.g., job descriptions and compensation programs); and migration toward greater organizational empowerment and more self-directed work teams. Still, your Patient Focused communications campaign will spearhead the cultural change process. As such, it will have the opportunity to make the very first impact. Basically, your communications can make or break your Patient Focused Care program from Day One. It's up to you--learn the lessons learned by others and your organization may follow the words of Marx rather than those of Brand: "Workers of the world, unite (on behalf of your Patient Focused Care program)!" Karl Marx.p6 "Workers of the world, fan out (in formation against your Patient Focused Care program)!" Stewart Brand. PMID:10133393

  15. Control of PM2.5 in Guangzhou during the 16th Asian Games period: implication for hazy weather prevention.

    PubMed

    Tao, Jun; Zhang, Leiming; Zhang, Zhisheng; Huang, Ruijin; Wu, Yunfei; Zhang, Renjian; Cao, Junji; Zhang, Yuanhang

    2015-03-01

    To evaluate the effectiveness of the integrated control measures for reducing PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 μm) and hazy weather, day- and night-time PM2.5 samples were collected at an urban site in Guangzhou during the 16th Asian Games period in November 2010. PM2.5 samples were subject to chemical analysis for major water-soluble ions, organic carbon (OC), element carbon (EC), and biomass burning tracers-anhydrosugar levoglucosan (LG). In addition, aerosol scattering coefficient (bsp) at dry condition and aerosol absorption coefficient (bap) and visibility at ambient condition were measured. The seven major control measures were effective for reducing PM2.5 mass concentration and improving visibility during the Asian Games period. All monitored air pollutants except PM2.5 satisfied the National Ambient Air Quality Standards (NAAQS). However, daily PM2.5 concentrations still exceeded the NAAQS on 47% of the days and hazy weather also occurred on 80% of the days during this period. One factor causing the high frequency of hazy weather occurrence was the increased relative humidity during the Asian Games period. To avoid hazy weather occurrence, new PM2.5 standard was recommended based on visibility calculations using three available aerosol hygroscopic curves previously obtained for this city. The recommended PM2.5 standard was 63 μgm(-3) under dry condition and lower than 42 μg m(-3) under humid condition (RH ≥ 70%). These recommended value s were much stricter than the NAAQS value of 75 μg m(-3). To reach the new standard, more rigorous control measures for coal industries should be established in the Pearl River Delta (PRD) region. PMID:25437953

  16. Control of PM2.5 in Guangzhou during the 16th Asian Games period: implication for hazy weather prevention.

    PubMed

    Tao, Jun; Zhang, Leiming; Zhang, Zhisheng; Huang, Ruijin; Wu, Yunfei; Zhang, Renjian; Cao, Junji; Zhang, Yuanhang

    2015-03-01

    To evaluate the effectiveness of the integrated control measures for reducing PM2.5 (aerosol particles with an aerodynamic diameter of less than 2.5 μm) and hazy weather, day- and night-time PM2.5 samples were collected at an urban site in Guangzhou during the 16th Asian Games period in November 2010. PM2.5 samples were subject to chemical analysis for major water-soluble ions, organic carbon (OC), element carbon (EC), and biomass burning tracers-anhydrosugar levoglucosan (LG). In addition, aerosol scattering coefficient (bsp) at dry condition and aerosol absorption coefficient (bap) and visibility at ambient condition were measured. The seven major control measures were effective for reducing PM2.5 mass concentration and improving visibility during the Asian Games period. All monitored air pollutants except PM2.5 satisfied the National Ambient Air Quality Standards (NAAQS). However, daily PM2.5 concentrations still exceeded the NAAQS on 47% of the days and hazy weather also occurred on 80% of the days during this period. One factor causing the high frequency of hazy weather occurrence was the increased relative humidity during the Asian Games period. To avoid hazy weather occurrence, new PM2.5 standard was recommended based on visibility calculations using three available aerosol hygroscopic curves previously obtained for this city. The recommended PM2.5 standard was 63 μgm(-3) under dry condition and lower than 42 μg m(-3) under humid condition (RH ≥ 70%). These recommended value s were much stricter than the NAAQS value of 75 μg m(-3). To reach the new standard, more rigorous control measures for coal industries should be established in the Pearl River Delta (PRD) region.

  17. An analysis on the concentration characteristics of PM2.5 in Seoul, Korea from 2005 to 2012

    NASA Astrophysics Data System (ADS)

    Lee, Miyeon

    2014-11-01

    PM2.5 is a big issue as it is considerably more harmful than other sizes of particulate matter. World Health Organization (WHO) recommends 25 μg m-3 as the daily average concentration, and 10 μg m-3 per day as an annual average. To keep up with global trends, it is first necessary to understand the current status and characteristics of PM2.5 concentrations in Korea. Using the PM2.5 data measured by Seoul Metropolitan City from November 2005 to March 2012, the author analyzed its statistical characteristics and correlations with other air pollutants. For the time period from 2005 to 2012, the annual average concentration of PM2.5 was 27 μg m-3, three times the WHO standard. Also, the daily average PM2.5 concentration of 215 days per year also exceeded the WHO standard. However, the number days exceeding the Korean daily average standard of 50 μg m-3 to be enacted in 2014 was only three. PM2.5 concentration had a high correlation (r = 0.84) with PM10, and also showed high correlations with gaseous pollutants, such as SO2, NO2, and CO, but not O3. This study suggests that the Korean government should strengthen their standard to match the criteria used by WHO.

  18. Ex vivo, microelectrode analysis of conduction through the AV node of wild-type and Nkx2-5 mutant mouse hearts as guided by a Cx40-eGFP transgenic reporter.

    PubMed

    Gazit, Avihu Z; Li, Alex; Choi, Jacob S; Miquerol, Lucile; Jay, Patrick Y

    2014-01-01

    Abstract Mutations of the cardiac transcription factor NKX2-5 cause hypoplastic development of the AV node and conduction block. How the anatomy of the mutant AV node relates to its function is unknown. We thus studied conduction through the AV nodal region in ex vivo preparations of wild-type and Nkx2-5(+/-) mouse hearts in which the central conduction system was highlighted by a transgenic Cx40-eGFP reporter. Fluorescence imaging guided electrode placement and pacing of the inferior and superior approaches to the AV node. Nkx2-5(+/-) hearts had a prolonged atrio-His interval compared to the wild type, consistent with previous in vivo observations. The conduction time to the His bundle from the Cx40(-) AV nodal region that is superior to and immediately adjacent to the Cx40(+) lower node is slightly, but not significantly greater in Nkx2-5(+/-) than wild-type hearts. A novel phenotype was also observed. Pacing the Cx40(-) inferior approach to the AV node with increasing stimulus strength led to progressive shortening of the stimulus-to-His conduction interval in wild-type but not Nkx2-5(+/-) hearts. The strength of pacing at the Cx40(-) superior approach had no effect on the conduction interval in either group. The prolonged AV delay in the Nkx2-5(+/-) heart appears to arise before the Cx40(+) lower node. Whether the pacing phenotype explains the mutant's conduction defect is uncertain, but the observation adds to a number of unique properties of the inferior approach to the AV node.

  19. Chemical composition of PM2.5 and PM10 in Mexico City during winter 1997.

    PubMed

    Chow, Judith C; Watson, John G; Edgerton, Sylvia A; Vega, Elizabeth

    2002-03-27

    PM2.5 and PM10 were measured over 24-h intervals at six core sites and at 25 satellite sites in and around Mexico City from 23 February to 22 March 1997. In addition, four 6-h samples were taken each day at three of the core sites. Sampling locations were selected to represent regional, central city, commercial, residential, and industrial portions of the city. Mass and light transmission concentrations were determined on all of the samples, while elements, ions and carbon were measured on approximately two-thirds of the samples. PM10 concentrations were highly variable, with almost three-fold differences between the highest and lowest concentrations. Fugitive dust was the major cause of PM10 differences, although carbon concentrations were also highly variable among the sampling sites. Approximately 50% of PM10 was in the PM2.5 fraction. The majority of PM mass was comprised of carbon, sulfate, nitrate, ammonium and crustal components, but in different proportions on different days and at different sites. The largest fine-particle components were carbonaceous aerosols, constituting approximately 50% of PM2.5 mass, followed by approximately 30% secondary inorganic aerosols and approximately 15% geological material. Geological material is the largest component of PM10, constituting approximately 50% of PM10 mass, followed by approximately 32% carbonaceous aerosols and approximately 17% secondary inorganic aerosols. Sulfate concentrations were twice as high as nitrate concentrations. Sulfate and nitrate were present as ammonium sulfate and ammonium nitrate. Approximately two-thirds of the ammonium sulfate measured in urban areas appears to have been transported from regions outside of the study domain, rather than formed from emissions in the urban area. Diurnal variations are apparent, with two-fold increases in concentration from night-time to daytime. Morning samples had the highest PM2.5 and PM10 mass, secondary inorganic aerosols and carbon concentrations

  20. Occupational Exposure to PM2.5 and Incidence of Ischemic Heart Disease

    PubMed Central

    Petersen, Maya; Costello, Sadie; Noth, Elizabeth M.; Hammond, Katherine; Cullen, Mark; van der Laan, Mark; Eisen, Ellen

    2015-01-01

    Background: We investigated the incidence of ischemic heart disease (IHD) in relation to accumulated exposure to particulate matter (PM) in a cohort of aluminum workers. We adjusted for time varying confounding characteristic of the healthy worker survivor effect, using a recently introduced method for the estimation of causal target parameters. Methods: Applying longitudinal targeted minimum loss-based estimation, we estimated the difference in marginal cumulative risk of IHD in the cohort comparing counterfactual outcomes if always exposed above to always exposed below a PM2.5 exposure cut-off. Analyses were stratified by sub-cohort employed in either smelters or fabrication facilities. We selected two exposure cut-offs a priori, at the median and 10th percentile in each sub-cohort. Results: In smelters, the estimated IHD risk difference after 15 years of accumulating PM2.5 exposure during follow-up was 2.9% (0.6%, 5.1%) using the 10th percentile cut-off of 0.10 mg/m3. For fabrication workers, the difference was 2.5% (0.8%, 4.1%) at the 10th percentile of 0.06 mg/m3. Using the median exposure cut-off, results were similar in direction but smaller in size. We present marginal incidence curves describing the cumulative risk of IHD over the course of follow-up for each sub-cohort under each intervention regimen. Conclusions: The accumulation of exposure to PM2.5 appears to result in higher risks of IHD in both aluminum smelter and fabrication workers. This represents the first longitudinal application of targeted minimum loss-based estimation, a method for generating doubly robust semi-parametric efficient substitution estimators of causal parameters, in the fields of occupational and environmental epidemiology. PMID:26079662

  1. Greater Influence of Aerosol on Cloud Microphysics

    NASA Astrophysics Data System (ADS)

    Jha, V.; Hudson, J. G.; Noble, S.

    2009-12-01

    CCN and cloud microphysics measurements are presented from four projects: RICO, PASE,ICE-L and POST. Correlations coefficients (R) between 1% supersaturation CCN concentrations and total cloud droplet concentrations were 0.80 in all four projects and for the combined data. R between CCN and larger cloud droplet concentrations progressively decreased with increasing sizes (Fig. 1A). At ~20 µm R was maximum negative and then reversed to smaller negative and even positive at larger drop sizes. R is positive for CCN with total cloud droplets because droplets are proportional to the concentrations of nuclei that they condensed upon, CCN. The negative R for CCN with larger droplets is due to competition among droplets for condensate. Competition for condensate is greater when CCN concentrations are higher and this limits droplet sizes, more so for higher concentrations. Negative R ensues because this reduces droplet concentrations above specific sizes to a greater extent for higher CCN concentrations. The greatest negative R thus occurs at the size range where droplet concentrations are the largest, the mode of the droplet size distributions. In Fig. 1 this is just beyond the average mode. At larger sizes droplet concentrations are lower (Fig. 1B) and thus there is less competition for condensate. The more numerous small sized droplets do not have enough surface area to affect the growth of the larger less numerous droplets. Thus at larger sizes with reduced competition, droplet concentrations are again proportional to the concentrations of the nuclei that they condensed upon. Often particle concentrations at various sizes are proportional. When this is the case there will be a positive R for CCN at 1% with such larger droplet concentrations such as PASE in Fig. 1A. Thus there are two directly conflicting influences on R; the usual positive R between CCN and droplets and the negative R due to competition for condensate. Thus lower R between CCN and droplet

  2. Hadron beam-beam diffusion in 2.5-D

    SciTech Connect

    Satogata, T.; Peggs, S.

    1999-07-01

    The standard analysis of modulational diffusion for general nonlinearities is qualitatively summarized, and compared to the particular case of a beam-beam simulation with two kicks per turn, plus tune modulation. A simulation with realistic Tevatron parameters shows amplitude growth over long timescales of order 10{sup 4} synchrotron periods. The simulated amplitude growth is qualitatively similar to the predictions of modulational diffusion, showing large discrete steps in the evolution speed as the tune distance from the nearest 2-D weak coupling resonance is varied. However, the simulation shows a fundamental difference in that the observed amplitude growth is approximately exponential in time, and not approximately root time as predicted in the standard analysis. Possible reasons for this and other discrepancies are briefly discussed.

  3. Polar organic tracers in PM2.5 aerosols from forests in eastern China

    NASA Astrophysics Data System (ADS)

    Wang, W.; Wu, M. H.; Li, L.; Zhang, T.; Li, H. J.; Wang, Y. J.; Liu, X. D.; Sheng, G. Y.; Claeys, M.; Fu, J. M.

    2008-06-01

    Photooxidation products of biogenic volatile organic compounds, mainly isoprene and monoterpenes, are significant sources of atmospheric particulate matter in forested regions. The objectives of this study were to examine time trends and diurnal variations of polar organic tracers for the photooxidation of isoprene and α-pinene to investigate whether they are linked with meteorological parameters or trace gases and to estimate their regional carbon contributions. PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) aerosol samples were collected from forests in eastern China and compared with data from forested sites in Europe and America. Aerosol sampling was conducted at four sites located along a gradient of ecological succession in four different regions of China, i.e. Changbai Mountain Nature Reserve (boreal-temperate), Chongming National Forest Park (temperate), Dinghu Mountain Nature Reserve (subtropical) and Jianfengling Nature Reserve (tropical) during summer periods when the meteorological conditions are believed to be favorable for photochemical processes. Fifty PM2.5 samples were collected; seventeen organic compounds, organic carbon (OC), elemental carbon and trace gases were measured. Results indicate that the concentration trends of the secondary organic compounds reflected those of the trace gases and meteorological parameters. The 24-h average concentrations of isoprene oxidation products, α-pinene oxidation products, sugars and sugar alcohols vary systematically along gradients of ecological succession, except malic acid which may have both biogenic and anthropogenic sources. The maximum carbon contribution of isoprene and α-pinene oxidation products to the OC was 2.4% (293 ng/m3, Changbai day-time) and 0.3% (41.3 ng/m3, Changbai night-time), respectively.

  4. [Greater trochanteric pain syndrome of the hip].

    PubMed

    Haviv, Barak; Bronak, Shlomo; Thein, Rafael

    2014-02-01

    Lateral pain of the hip with point tenderness at the Greater Trochanter is a common musculoskeletal complaint. It is frequently diagnosed as trochanteric bursitis; however, this term is inaccurate because of evident non-inflammatory pathologies, particularly of the abductor tendons of the hip. It is important to differentiate this extra-articular source from an intra-articular or a lower back source of pain. Imaging is useful in cases of trauma, prolonged pain or uncertain diagnosis. Non-operative treatment that involves modifying activities, physiotherapy, analgesics, steroid injections and shock wave therapy is usually helpful. Nevertheless, despite the above treatments, about one third of the patients suffer from chronic pain and disability. These patients may be candidates for operative intervention. Currently, there are endoscopic surgical techniques for local decompression, bursectomy and suture of torn tendons similar to surgery used in the shoulder. PMID:24716427

  5. Planning for greater-confinement disposal

    SciTech Connect

    Gilbert, T.L.; Luner, C.; Meshkov, N.K.; Trevorrow, L.E.; Yu, C.

    1984-01-01

    This contribution is a progress report for preparation of a document that will summarize procedures and technical information needed to plan for and implement greater-confinement disposal (GCD) of low-level radioactive waste. Selection of a site and a facility design (Phase I), and construction, operation, and extended care (Phase II) will be covered in the document. This progress report is limited to Phase I. Phase I includes determination of the need for GCD, design alternatives, and selection of a site and facility design. Alternative designs considered are augered shafts, deep trenches, engineered structures, high-integrity containers, hydrofracture, and improved waste form. Design considerations and specifications, performance elements, cost elements, and comparative advantages and disadvantages of the different designs are covered. Procedures are discussed for establishing overall performance objectives and waste-acceptance criteria, and for comparative assessment of the performance and cost of the different alternatives. 16 references.

  6. Greater confinement disposal of radioactive wastes

    SciTech Connect

    Trevorrow, L.E.; Gilbert, T.L.; Luner, C.; Merry-Libby, P.A.; Meshkov, N.K.; Yu, C.

    1985-01-01

    Low-level radioactive waste (LLW) includes a broad spectrum of different radionuclide concentrations, half-lives, and hazards. Standard shallow-land burial practice can provide adequate protection of public health and safety for most LLW. A small volume fraction (approx. 1%) containing most of the activity inventory (approx. 90%) requires specific measures known as greater-confinement disposal (GCD). Different site characteristics and different waste characteristics - such as high radionuclide concentrations, long radionuclide half-lives, high radionuclide mobility, and physical or chemical characteristics that present exceptional hazards - lead to different GCD facility design requirements. Facility design alternatives considered for GCD include the augered shaft, deep trench, engineered structure, hydrofracture, improved waste form, and high-integrity container. Selection of an appropriate design must also consider the interplay between basic risk limits for protection of public health and safety, performance characteristics and objectives, costs, waste-acceptance criteria, waste characteristics, and site characteristics.

  7. Health and Greater Manchester in Historical Perspective

    PubMed Central

    Snow, Stephanie J.

    2015-01-01

    This article maps the history of health organisation across Greater Manchester (GM), primarily since the Second World War, to show how against a continuing backdrop of health inequalities, services have been driven (and constrained) by the needs and the politics of each period. Defining ‘success’ as benefits for patients the article identifies examples such as Salford’s mental health services (1950s and 1960s), public health in North Manchester (1970s and 1980s), the creation of centres for diabetes, sickle-cell and thalassaemia (1980s) and the formation of the Joint Health Unit in 2002. What this history shows is that over the period the common factors influencing the ‘success’ of health organisation across GM have been the championing of particular issues by multi-disciplinary groups working across health and social care and stability in structures and personnel. PMID:27499557

  8. A High-Resolution Two-Stage Satellite Model to Estimate PM2.5 Concentrations in China

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Ma, Z.; Hu, X.; Yang, K.

    2014-12-01

    With the rapid economic development and urbanization, severe and widespread PM2.5 pollution in China has attracted nationwide attention. Study of the health impact of PM2.5 exposure has been hindered, however, by the limited coverage of ground measurements from recently established regulatory monitoring networks. Estimating ground-level PM2.5 from satellite remote sensing is a promising new method to evaluate the spatial and temporal patterns of PM2.5 exposure. We developed a two-stage spatial statistical model to estimate daily mean PM2.5 concentrations at 10 km resolution in 2013 in China using MODIS Collection 6 AOD, assimilated meteorology, population density, and land use parameters. A custom inverse variance weighting approach was developed to combine MODIS Dark Target (DT) and Deep Blue (DB) AOD to optimize coverage. Compared with the AERONET AOD measurements, our combined AOD (R2=0.80, mean bias = 0.07) performs similarly to MODIS' combined AOD (R2=0.81, mean bias =0.07), but has 90% greater coverage. We used the first-stage linear mixed effect model to represent the temporal variability of PM2.5 and the second-stage generalized additive model to represent its spatial contrast. The overall model cross-validation R2 and relative prediction error are 0.80 and 30%, respectively. PM2.5 levels exhibit strong seasonal patterns, with the highest national mean concentrations in winter (75 µg/m3) and the lowest in summer (30 µg/m3). Elevated annual mean PM2.5 levels are predicted in North China Plain and Sichuan Basin, with the maximum annual PM2.5 concentrations higher than 130 µg/m3 and 110 µg/m3, respectively. Our results also indicates that over 94% of the Chinese population lives in areas that exceed the WHO Air Quality Interim Target-1 standard (35 μg/m3). The exceptions include Taiwan, Hainan, Yunnan, Tibet, and North Inner Mongolia.

  9. 'Superplane!' High Speed Civil Transport (pt 2/5)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The High Speed Civil Transport (HSCT). This light-hearted promotional piece explains what the HSCT 'Superplane!' is and what advantages it will have over current aircraft. As envisioned, the HSCT is a next-generation supersonic (faster than the speed of sound) passenger jet that would fly 300 passengers at more than 1,500 miles per hour -- more than twice the speed of sound. It will cross the Pacific or Atlantic in less than half the time of modern subsonic jets, and at a ticket price less than 20 percent above comparable, slower flights

  10. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5...

  11. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Test Specifications for PM10, PM2.5 and PM10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of Environment... Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for PM10, PM2.5...

  12. Thermal evolution of the Greater Himalaya, Garhwal, India

    NASA Astrophysics Data System (ADS)

    Hodges, K. V.; Silverberg, David Scott

    1988-06-01

    The hanging wall of the Main Central Thrust (MCT) in Garhwal, India (roughly 79°N-80°E; 30°N-31°N), exhibits an inverted metamorphic gradient: sillimanite ± potassium feldspar assemblages near the top of the hanging wall, or Greater Himalayan sequence, are underlain by kyanite grade rocks near the fault. Textural relationships in pelitic samples from the Alaknanda and Dhauli river valleys indicate that the "inversion" is the product of two distinct metamorphic events: an early Harrovian event (M1), which affected the entire Greater, Himalayan sequence and a later Buchan event (M2), the effects of which are most obvious in the upper part of the sequence. Rim thermobarometry, garnet inclusion thermobarometry, and thermodynamic modeling of garnet zoning reveal that the basal portions of the metamorphic sequence experienced peak M1 conditions of >900 K and >960 MPa (roughly 36 km depth) before following an "erosion controlled" uplift path (e.g., England and Richardson, 1977). M2 metamorphic temperatures in the upper part of the sequence also exceeded 900 K, but maximum pressures (317-523 MPa) indicate paleodepths of only 12-19 km. Calculated pressure-temperature paths indicate that M2 was characterized by temperature increases of >80 K and roughly 5 km of tectonic burial We attribute M1 to tectonic burial of the Greater Himalayan sequence during the early stages of India-Eurasia collision. We believe that the uplift and cooling path of the sequence was interrupted in late Oligocene(?) - Miocene time by a second burial and heating event (M2) related to thrust imbrications in southern Tibet. This burial was coincident with the generation of leucogranites, which are abundant near the top of the Greater Himalayan sequence but are virtually absent near the MCT. Field relations do not constrain whether the leucogranites were derived from some presently unexposed portion of the Greater Himalayan sequence and were injected at their present structural level, or were melted

  13. Chemical characteristics of PM2.5 during haze episodes in Beijing

    NASA Astrophysics Data System (ADS)

    Shen, Rongrong; Schaefer, Klaus; Suppan, Peter; Wang, Yuesi; Schnelle-Kreis, Jürgen; Shao, Longyi; Emeis, Stefan

    2014-05-01

    Haze episodes have become much more frequent in Beijing and have received more attention during the past decade because of its influences on visibility and human health. Due to the chemical characteristics and sources of haze, which are different from the normal urban aerosols, studies of haze pollution become more important for the control of air pollution in Beijing. This study aims to investigate the chemical characteristics of PM2.5 during haze episodes in Beijing in 2013 spring and the possible sources of chemical compounds during haze episodes. Two sequential High-Volume Samplers (Digitel DHA-80, Hegnau, Switzerland) were used to collect PM2.5 samples in Beijing automatically from 10 April to 8 June 2013. The inorganic elements, inorganic water-soluble ions, EC and OC of PM2.5 were analyzed by ICP-MS, IC and thermal/optical carbon analyzers respectively. Three haze episodes were found: 18 to 25 April, 3 to 9 May and 1 to 8 June. The average PM2.5 mass concentration during haze days was 140 µg m-3 while 45 µg m-3 during clear days. SO42-, NO3-, NH4+, Cl-, K+, Cu, Ni, Zn, As, Cd, Tl, Pb, EC and OC, mass concentrations increased during haze days, compared with concentrations during clear days. The main increase is that secondary inorganic pollutant mass concentrations (NO3-, SO42- and NH4+) were 6 times higher and mass percentages were 2 times higher. This indicates that the major chemical species of PM2.5 during haze episodes are originated from anthropogenic sources. NO3-, SO42- and NH4+ are basically formed by a gas-to-particle formation processes on the basis of chemical reactions of precursor gases. Mass ratio of NO3-/SO42- is widely used as an indicator to determine the importance of mobile sources and stationary sources of sulphur and nitrogen. The mass ratio of NO3-/SO42- during haze days (0.82) was higher than during clear days (0.68) suggesting that vehicle emission is an important reason for haze in Beijing. OC/EC mass ratio higher than 2 indicates

  14. Concentrations and emission factors for PM2.5 and PM10 from road traffic in Sweden

    NASA Astrophysics Data System (ADS)

    Ferm, Martin; Sjöberg, Karin

    2015-10-01

    PM10 concentrations exceed the guidelines in some Swedish cities and the limit values will likely be further reduced in the future. In order to gain more knowledge of emission factors for road traffic and concentrations of PM10 and PM2.5, existing monitoring stations in two cities, Gothenburg and Umeå, with international E-road thoroughfares, were complemented with some PM2.5 measurements. Emission factors for PM10 and PM2.5 were estimated using NOX as a tracer. Monitoring data from kerbside and urban background sites in Gothenburg during 2006-2010 and in Umeå during 2006-2012 were used. NOX emissions were estimated from the traffic flow and emission factors calculated from the HBEFA3.1 model. PM2.5 constitutes the finer part of PM10. Emissions of the coarser part of PM10 (PM10-PM2.5) are suppressed when roads are wet and show a maximum during spring when the roads dry up and studded tyres are still used. Less than 1% of the road wear caused by studded tyres give rise to airborne PM2.5-10 particles. The NOX emission factors decrease with time in the used model, due to the renewal of the vehicle fleet. However, the NOX concentrations resulting from the roads show no clear trend. The air dispersion is an important factor controlling the PM concentration near the road. The dispersion has a minimum in winter and during midnight. The average street level concentrations of PM10 and PM2.5 in Gothenburg were 21 ± 20 and 8 ± 6 μg m-3 respectively, which is 36% and 22% higher than the urban background concentrations. Despite the four times lower traffic flow in Umeå compared to Gothenburg, the average particle concentrations were very similar; 21 ± 31 and 7 ± 5 μg m-3 for PM10 and PM2.5 respectively. These concentrations were, however, 108% and 55% higher than the urban background concentrations in Umeå. The emission factors for PM10 decreased with time, and the average factor was 0.06 g km-1 vehichle-1. The emission factors for PM2.5 are very uncertain due to the

  15. Spectral investigations of 2,5-difluoroaniline by using mass, electronic absorption, NMR, and vibrational spectra

    NASA Astrophysics Data System (ADS)

    Kose, Etem; Karabacak, Mehmet; Bardak, Fehmi; Atac, Ahmet

    2016-11-01

    One of the most significant aromatic amines is aniline, a primary aromatic amine replacing one hydrogen atom of a benzene molecule with an amino group (NH2). This study reports experimental and theoretical investigation of 2,5-difluoroaniline molecule (2,5-DFA) by using mass, ultraviolet-visible (UV-vis), 1H and 13C nuclear magnetic resonance (NMR), Fourier transform infrared and Raman (FT-IR and FT-Raman) spectra, and supported with theoretical calculations. Mass spectrum (MS) of 2,5-DFA is presented with their stabilities. The UV-vis spectra of the molecule are recorded in the range of 190-400 nm in water and ethanol solvents. The 1H and 13C NMR chemical shifts are recorded in CDCl3 solution. The vibrational spectra are recorded in the region 4000-400 cm-1 (FT-IR) and 4000-10 cm-1 (FT-Raman), respectively. Theoretical studies are underpinned the experimental results as described below; 2,5-DFA molecule is optimized by using B3LYP/6-311++G(d,p) basis set. The mass spectrum is evaluated and possible fragmentations are proposed based on the stable structure. The electronic properties, such as excitation energies, oscillator strengths, wavelengths, frontier molecular orbitals (FMO), HOMO and LUMO energies, are determined by time-dependent density functional theory (TD-DFT). The electrostatic potential surface (ESPs), density of state (DOS) diagrams are also prepared and evaluated. In addition to these, reduced density gradient (RDG) analysis is performed, and thermodynamic features are carried out theoretically. The NMR spectra (1H and 13C) are calculated by using the gauge-invariant atomic orbital (GIAO) method. The vibrational spectra of 2,5-DFA molecule are obtained by using DFT/B3LYP method with 6-311++G(d,p) basis set. Fundamental vibrations are assigned based on the potential energy distribution (PED) of the vibrational modes. The nonlinear optical properties (NLO) are also investigated. The theoretical and experimental results give a detailed description of

  16. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia

    PubMed Central

    Enkhbat, Undarmaa; Rule, Ana M.; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D’Ann L.

    2016-01-01

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40–60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.–11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17–99) μg/m3, and 100 (95% CI: 67–187) μg/m3 in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39–297) μg/m3 and 127.8 (95% CI: 86–190) μg/m3 in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant

  17. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia.

    PubMed

    Enkhbat, Undarmaa; Rule, Ana M; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D'Ann L

    2016-02-15

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40-60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.-11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17-99) μg/m³, and 100 (95% CI: 67-187) μg/m³ in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39-297) μg/m³ and 127.8 (95% CI: 86-190) μg/m³ in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant difference

  18. Source sector and region contributions to BC and PM2.5 in Central Asia

    NASA Astrophysics Data System (ADS)

    Kulkarni, S.; Sobhani, N.; Miller-Schulze, J. P.; Shafer, M. M.; Schauer, J. J.; Solomon, P. A.; Saide, P. E.; Spak, S. N.; Cheng, Y. F.; Denier van der Gon, H. A. C.; Lu, Z.; Streets, D. G.; Janssens-Maenhout, G.; Wiedinmyer, C.; Lantz, J.; Artamonova, M.; Chen, B.; Imashev, S.; Sverdlik, L.; Deminter, J. T.; Adhikary, B.; D'Allura, A.; Wei, C.; Carmichael, G. R.

    2014-05-01

    . Aerosols at these sites are shown to reflect dust, biomass burning and anthropogenic sources from Europe, South, East and CA, and Russia depending on the time period. Simulations for a reference 2030 emission scenario based on pollution abatement measures already committed to in current legislation show that PM2.5 and BC concentrations in the region increase, with BC growing more than PM2.5 on a relative basis. This suggests that both the health impacts and the climate warming associated with these particles may increase over the next decades unless additional control measures are taken. The importance of observations in CA to help characterize the changes that are rapidly taking place in the region are discussed.

  19. Source sector and region contributions to BC and PM2.5 in Central Asia

    NASA Astrophysics Data System (ADS)

    Kulkarni, S.; Sobhani, N.; Miller-Schulze, J. P.; Shafer, M. M.; Schauer, J. J.; Solomon, P. A.; Saide, P. E.; Spak, S. N.; Cheng, Y. F.; Denier van der Gon, H. A. C.; Lu, Z.; Streets, D. G.; Janssens-Maenhout, G.; Wiedinmyer, C.; Lantz, J.; Artamonova, M.; Chen, B.; Imashev, S.; Sverdlik, L.; Deminter, J. T.; Adhikary, B.; D'Allura, A.; Wei, C.; Carmichael, G. R.

    2015-02-01

    . Aerosols at these sites are shown to reflect dust, biomass burning, and anthropogenic sources from Europe; South, East, and Central Asia; and Russia depending on the time period. Simulations for a reference 2030 emission scenario based on pollution abatement measures already committed to in current legislation show that PM2.5 and BC concentrations in the region increase, with BC growing more than PM2.5 on a relative basis. This suggests that both the health impacts and the climate warming associated with these particles may increase over the next decades unless additional control measures are taken. The importance of observations in CA to help characterize the changes that are rapidly taking place in the region are discussed.

  20. Exposure to PM2.5 and Blood Lead Level in Two Populations in Ulaanbaatar, Mongolia.

    PubMed

    Enkhbat, Undarmaa; Rule, Ana M; Resnick, Carol; Ochir, Chimedsuren; Olkhanud, Purevdorj; Williams, D'Ann L

    2016-02-01

    Approximately 60% of the households in Ulaanbaatar live in gers (a traditional Mongolian dwelling) in districts outside the legal limits of the city, without access to basic infrastructure, such as water, sewage systems, central heating, and paved roads, in contrast to apartment residents. This stark difference in living conditions creates different public health challenges for Ulaanbaatar residents. Through this research study we aim to test our hypothesis that women living in gers burning coal in traditional stoves for cooking and heating during the winter are exposed to higher concentrations of airborne PM2.5 than women living in apartments in Ulaanbaatar, Mongolia, and this exposure may include exposures to lead in coal with effects on blood lead levels. This cross-sectional study recruited a total of 50 women, 40-60 years of age, from these two settings. Air sampling was carried out during peak cooking and heating times, 5:00 p.m.-11:00 p.m., using a direct-reading instrument (TSI SidePak™) and integrated polytetrafluoroethylene (PTFE) filters using the SKC Personal Environmental Monitor. Blood lead level (BLL) was measured using a LeadCare II rapid field test method. In our study population, measured PM2.5 geometric mean (GM) concentrations using the SidePak™ in the apartment group was 31.5 (95% CI:17-99) μg/m³, and 100 (95% CI: 67-187) μg/m³ in ger households (p < 0.001). The GM integrated gravimetric PM2.5 concentrations in the apartment group were 52.8 (95% CI: 39-297) μg/m³ and 127.8 (95% CI: 86-190) μg/m³ in ger households (p = 0.004). The correlation coefficient for the SidePak™ PM2.5 concentrations and filter based PM2.5 concentrations was r = 0.72 (p < 0.001). Blood Lead Levels were not statistically significant different between apartment residents and ger residents (p = 0.15). The BLL is statistically significant different (p = 0.01) when stratified by length of exposures outside of the home. This statistically significant difference

  1. Gravimetric and chemical features of airborne PM 10 AND PM 2.5 in mainland Portugal.

    PubMed

    Freitas, M C; Farinha, M M; Ventura, M G; Almeida, S M; Reis, M A; Pacheco, A M G

    2005-10-01

    This paper describes concentration amounts of arsenic (As), particulate mercury (Hg), nickel (Ni) and lead (Pb) in PM(10) and PM(2.5), collected since 1993 by the Technological and Nuclear Institute (ITN) at different locations in mainland Portugal, featuring urban, industrial and rural environments, and a control as well. Most results were obtained in the vicinity of coal- and oil-fired power plants. Airborne mass concentrations were determined by gravimetry. As and Hg concentrations were obtained through instrumental neutron activation analysis (INAA), and Ni and Pb concentrations through proton-induced X-ray emission (PIXE). Comparison with the EU (European Union) and the US EPA (United States Environmental Protection Agency) directives for Ambient Air has been carried out, even though the sampling protocols herein--set within the framework of ITN's R&D projects and/or monitoring contracts--were not consistent with the former regulations. Taking this into account, 1) the EU daily limit for PM(10) was exceeded a few times in all sites except the control, even if the number of times was still inferior to the allowed one; 2) the EU annual mean for PM(10) was exceeded at one site; 3) the EPA daily limit for PM(2.5) was exceeded one time at three sites; 4) the EPA annual mean for PM(2.5) was exceeded at most sites; 5) the inner-Lisbon site approached or exceeded the legislated PMs; 6) Pb levels stayed far below the EU limit value; and 7) concentrations of As, Ni and Hg were also far less than the reference values adopted by EU. In every location, Ni appeared more concentrated in PM(2.5) than in coarser particles, and its levels were not that different from site to site, excluding the control. The highest As and Hg concentrations were found in the neighbourhood of the coal-fired, utility power plants. The results may be viewed as a "worst-case scenario" of atmospheric pollution, since they have been obtained in busy urban-industrial areas and/or near major power

  2. Using high-resolution satellite aerosol optical depth to estimate daily PM2.5 geographical distribution in Mexico City

    PubMed Central

    Just, Allan C.; Wright, Robert O.; Schwartz, Joel; Coull, Brent A.; Baccarelli, Andrea A.; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-01-01

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to the Mexico City area, a region with higher PM2.5 than most US and European urban areas. Using a novel 1 km resolution AOD product from the MODIS instrument, we constructed daily predictions across the greater Mexico City area for 2004–2014. We calibrated the association of AOD to PM2.5 daily using municipal ground monitors, land use, and meteorological features. Predictions used spatial and temporal smoothing to estimate AOD when satellite data were missing. Our model performed well, resulting in an out-of-sample cross validation R2 of 0.724. Cross-validated root mean squared prediction error (RMSPE) of the model was 5.55 μg/m3. This novel model reconstructs long- and short-term spatially resolved exposure to PM2.5 for epidemiological studies in Mexico City. PMID:26061488

  3. Using High-Resolution Satellite Aerosol Optical Depth To Estimate Daily PM2.5 Geographical Distribution in Mexico City.

    PubMed

    Just, Allan C; Wright, Robert O; Schwartz, Joel; Coull, Brent A; Baccarelli, Andrea A; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-07-21

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to the Mexico City area, a region with higher PM2.5 than most U.S. and European urban areas. Using a novel 1 km resolution AOD product from the MODIS instrument, we constructed daily predictions across the greater Mexico City area for 2004-2014. We calibrated the association of AOD to PM2.5 daily using municipal ground monitors, land use, and meteorological features. Predictions used spatial and temporal smoothing to estimate AOD when satellite data were missing. Our model performed well, resulting in an out-of-sample cross-validation R(2) of 0.724. Cross-validated root-mean-squared prediction error (RMSPE) of the model was 5.55 μg/m(3). This novel model reconstructs long- and short-term spatially resolved exposure to PM2.5 for epidemiological studies in Mexico City. PMID:26061488

  4. Comparison of Four Ground-Level PM2.5 Estimation Models Using PARASOL Aerosol Optical Depth Data from China.

    PubMed

    Guo, Hong; Cheng, Tianhai; Gu, Xingfa; Chen, Hao; Wang, Ying; Zheng, Fengjie; Xiang, Kunshen

    2016-02-01

    Satellite remote sensing is of considerable importance for estimating ground-level PM2.5 concentrations to support environmental agencies monitoring air quality. However, most current studies have focused mainly on the application of MODIS aerosol optical depth (AOD) to predict PM2.5 concentrations, while PARASOL AOD, which is sensitive to fine-mode aerosols over land surfaces, has received little attention. In this study, we compared a linear regression model, a quadratic regression model, a power regression model and a logarithmic regression model, which were developed using PARASOL level 2 AOD collected in China from 18 January 2013 to 10 October 2013. We obtained R (correlation coefficient) values of 0.64, 0.63, 0.62, and 0.57 for the four models when they were cross validated with the observed values. Furthermore, after all the data were classified into six levels according to the Air Quality Index (AQI), a low level of statistical significance between the four empirical models was found when the ground-level PM2.5 concentrations were greater than 75 μg/m³. The maximum R value was 0.44 (for the logarithmic regression model and the power model), and the minimum R value was 0.28 (for the logarithmic regression model and the power model) when the PM2.5 concentrations were less than 75 μg/m³. We also discussed uncertainty sources and possible improvements. PMID:26840329

  5. Comparison of Four Ground-Level PM2.5 Estimation Models Using PARASOL Aerosol Optical Depth Data from China

    PubMed Central

    Guo, Hong; Cheng, Tianhai; Gu, Xingfa; Chen, Hao; Wang, Ying; Zheng, Fengjie; Xiang, Kunshen

    2016-01-01

    Satellite remote sensing is of considerable importance for estimating ground-level PM2.5 concentrations to support environmental agencies monitoring air quality. However, most current studies have focused mainly on the application of MODIS aerosol optical depth (AOD) to predict PM2.5 concentrations, while PARASOL AOD, which is sensitive to fine-mode aerosols over land surfaces, has received little attention. In this study, we compared a linear regression model, a quadratic regression model, a power regression model and a logarithmic regression model, which were developed using PARASOL level 2 AOD collected in China from 18 January 2013 to 10 October 2013. We obtained R (correlation coefficient) values of 0.64, 0.63, 0.62, and 0.57 for the four models when they were cross validated with the observed values. Furthermore, after all the data were classified into six levels according to the Air Quality Index (AQI), a low level of statistical significance between the four empirical models was found when the ground-level PM2.5 concentrations were greater than 75 μg/m3. The maximum R value was 0.44 (for the logarithmic regression model and the power model), and the minimum R value was 0.28 (for the logarithmic regression model and the power model) when the PM2.5 concentrations were less than 75 μg/m3. We also discussed uncertainty sources and possible improvements. PMID:26840329

  6. Using High-Resolution Satellite Aerosol Optical Depth To Estimate Daily PM2.5 Geographical Distribution in Mexico City.

    PubMed

    Just, Allan C; Wright, Robert O; Schwartz, Joel; Coull, Brent A; Baccarelli, Andrea A; Tellez-Rojo, Martha María; Moody, Emily; Wang, Yujie; Lyapustin, Alexei; Kloog, Itai

    2015-07-21

    Recent advances in estimating fine particle (PM2.5) ambient concentrations use daily satellite measurements of aerosol optical depth (AOD) for spatially and temporally resolved exposure estimates. Mexico City is a dense megacity that differs from other previously modeled regions in several ways: it has bright land surfaces, a distinctive climatological cycle, and an elevated semi-enclosed air basin with a unique planetary boundary layer dynamic. We extend our previous satellite methodology to the Mexico City area, a region with higher PM2.5 than most U.S. and European urban areas. Using a novel 1 km resolution AOD product from the MODIS instrument, we constructed daily predictions across the greater Mexico City area for 2004-2014. We calibrated the association of AOD to PM2.5 daily using municipal ground monitors, land use, and meteorological features. Predictions used spatial and temporal smoothing to estimate AOD when satellite data were missing. Our model performed well, resulting in an out-of-sample cross-validation R(2) of 0.724. Cross-validated root-mean-squared prediction error (RMSPE) of the model was 5.55 μg/m(3). This novel model reconstructs long- and short-term spatially resolved exposure to PM2.5 for epidemiological studies in Mexico City.

  7. [Estimation of PM2.5 over eastern China from MODIS aerosol optical depth using the back propagation neural network].

    PubMed

    Guo, Jian-Ping; Wu, Ye-Rong; Zhang, Xiao-Ye; Li, Xiao-Wen

    2013-03-01

    With the fast economic development in China in recent years, air pollutions are becoming increasingly serious. It is, therefore, imperative to develop new technology to solve this issue. Due to the wide spatial coverage of satellite remote sensing, along with the relatively lower cost compared to ground-based in situ aerosol measurements, satellite retrieved aerosol optical depth (AOD) is widely recognized as a good surrogate of surface PM2.5 concentrations. In this study, two years (2007-2008) of AOD data from moderate resolution imaging spectroradiometer (MODIS) onboard Terra at five observational sites of China (Benxi, Zhengzhou, Lushan, Nanning, Guilin), combined with five meteorological factors such as wind speed, wind direction, temperature humidity and planetary boundary height, were used as important input to establish the Back Propagation (BP) neural networks model, which was applied to estimate PM2.5. Afterwards, the model estimated PM2.5 was validated by in situ PM2.5 measurements from the five sites. Specially, scatter analysis showed that the linear correlation coefficient (R) between ground PM2.5 observation and model estimated PM2.5 at Lushan was the highest (R = 0.6), whereas the R values at the four other sites were lower, ranging from 0.43 to 0.49. Time series validations were performed as well, indicating that the R value significantly varied from day to day. However, the R value could be significantly improved by fitting the five-day moving average ground observation values against the model estimated PM2.5 data. Also, the R value at Lushan was the highest (R = 0.83), suggesting that MODIS AOD can be used to monitor PM2.5 by the BP networks model developed in this study.

  8. Greater Green River Basin Production Improvement Project

    SciTech Connect

    DeJarnett, B.B.; Lim, F.H.; Calogero, D.

    1997-10-01

    The Greater Green River Basin (GGRB) of Wyoming has produced abundant oil and gas out of multiple reservoirs for over 60 years, and large quantities of gas remain untapped in tight gas sandstone reservoirs. Even though GGRB production has been established in formations from the Paleozoic to the Tertiary, recent activity has focused on several Cretaceous reservoirs. Two of these formations, the Ahnond and the Frontier Formations, have been classified as tight sands and are prolific producers in the GGRB. The formations typically naturally fractured and have been exploited using conventional well technology. In most cases, hydraulic fracture treatments must be performed when completing these wells to to increase gas production rates to economic levels. The objectives of the GGRB production improvement project were to apply the concept of horizontal and directional drilling to the Second Frontier Formation on the western flank of the Rock Springs Uplift and to compare production improvements by drilling, completing, and testing vertical, horizontal and directionally-drilled wellbores at a common site.

  9. Malaria situation in the Greater Mekong Subregion.

    PubMed

    Hewitt, Sean; Delacollette, Charles; Chavez, Irwin

    2013-01-01

    The epidemiology of malaria in the Greater Mekong Subregion is complex and rapidly evolving. Malaria control and elimination efforts face a daunting array of challenges including multidrug-resistant parasites. This review presents secondary data collected by the national malaria control programs in the six countries between 1998 and 2010 and examines trends over the last decade. This data has a number of limitations: it is derived exclusively from public sector health facilities; falciparum-specific and then pan-specific rapid diagnostic tests were introduced during the period under review; and, recently there has been a massive increase in case detection capability as a result of increased funding. It therefore requires cautious interpretation. A series of maps are presented showing trends in incidence, mortality and proportion of cases caused by Plasmodium falciparum over the last decade. A brief overview of institutional and implementation arrangements, historical background, demographics and key issues affecting malaria epidemiology is provided for each country. National malaria statistics for 2010 are presented and their robustness discussed in terms of the public sector's share of cases and other influencing factors such as inter-country variations in risk stratification, changes in diagnostic approach and immigration. Targets are presented for malaria control and where appropriate for elimination. Each country's artemisinin resistance status is described. The epidemiological trends presented reflect the improvement in the malaria situation, however the true malaria burden is as yet unknown. There is a need for continuing strengthening and updating of surveillance and response systems. PMID:24159830

  10. Water quality improvement plan for Greater Vancouver

    SciTech Connect

    Foellmi, S.N. . Environmental Div.); Neden, D.G. ); Dawson, R.N. )

    1993-10-01

    The Greater Vancouver Regional District commissioned an 18-month planning and predesign study to define the components in a comprehensive water and predesign study to define the components in a comprehensive water quality improvement plan for its 2,500-ML/d (660-mgd) system. The study included three primary tasks: (1) predesign of disinfection and corrosion control facilities, (2) a 12-month pilot testing program using parallel pilot plants at the Seymour and Capilano water supply reservoirs, and (3) planning for future filtration plants. The results of the study identified chlorine, ammonia, sulfur dioxide, soda ash, and carbon dioxide in a two-stage treatment approach as the recommended disinfection and corrosion control scheme for the low-pH, low-alkalinity water supplies. The pilot-plant studies confirmed that direct filtration using deep-bed monomedium filters operating at a loading rate of 22.5 m/h provided excellent treatment performance and productivity over a wide range of raw-water quality. Ozonation was studied extensively and found not to be beneficial in the overall treatment performance. The phased improvement plan for the disinfection, corrosion control, and filtration facilities has an estimated capital cost of about Can$459 million.

  11. Chemical composition of size-resolved particulate matter at near-freeway and urban background sites in the greater Beirut area

    NASA Astrophysics Data System (ADS)

    Daher, Nancy; Saliba, Najat A.; Shihadeh, Alan L.; Jaafar, Malek; Baalbaki, Rima; Sioutas, Constantinos

    2013-12-01

    To characterize road-traffic emissions in the greater Beirut area, size-resolved PM10-2.5, PM2.5-0.25 and PM0.25 samples were concurrently collected at near-freeway and background sites. While particle mass levels were 1.3-2.6 times greater at the roadside than background location, PM10-2.5 and PM0.25 prevailed at both sites (36-43% of PM10). A chemical mass closure showed that PM10-2.5 was mostly composed of crustal material, contributing to 12-23% of its mass across sites. On the other hand, in PM2.5-0.25 and PM0.25, organic matter (46-56%) was dominant at the roadside location, while secondary ions (SI, 54-68%) were more abundant at the background site. In the vicinity of the freeway, organic carbon (OC) levels varied from 4 μg m-3 in PM10-2.5 to 10.1 μg m-3 in PM0.25, exceeding those at the background site by 4-7 times. In contrast, OC was largely water-soluble at the background location, with its water-soluble fraction displaying comparable PM2.5-0.25- and PM0.25-concentrations at both sites, corroborating its regional secondary origin. PM0.25-elemental carbon (EC), which dominated overall EC mass, was 7-fold greater at the near-freeway than background location, indicating a contribution from diesel or also smoking vehicles to road-traffic emissions. PM2.5-SI showed fairly uniform concentrations across sites, confirming their mainly regional source. Polycyclic aromatic hydrocarbons (PAHs) were undetected at the coastal background site, whereas their levels peaked at 11.5 ng m-3 in proximity to the freeway, with the majority confined to PM0.25. Compared to other roadways, organic compounds at the freeway location exhibited high hopanes plus steranes-to-total carbon ratios (0.16-1.1 ng μg-1), indicative of different engine configurations, fleet or also lubricating oil formulation. At both locations, PM0.25-bound n-alkanes (C19-C34) showed a predominance of high molecular weight homologues and no carbon number preference, suggesting their likely road dust

  12. Effects of the Particulate Matter2.5 (PM2.5) on Lipoprotein Metabolism, Uptake and Degradation, and Embryo Toxicity

    PubMed Central

    Kim, Jae-Yong; Lee, Eun-Young; Choi, Inho; Kim, Jihoe; Cho, Kyung-Hyun

    2015-01-01

    Particulate matter2.5 (PM2.5) is notorious for its strong toxic effects on the cardiovascular, skin, nervous, and reproduction systems. However, the molecular mechanism by which PM2.5 aggravates disease progression is poorly understood, especially in a water-soluble state. In the current study, we investigated the putative physiological effects of aqueous PM2.5 solution on lipoprotein metabolism. Collected PM2.5 from Seoul, Korea was dissolved in water, and the water extract (final 3 and 30 ppm) was treated to human serum lipoproteins, macrophages, and dermal cells. PM2.5 extract resulted in degradation and aggregation of high-density lipoprotein (HDL) as well as low-density lipoprotein (LDL); apoA-I in HDL aggregated and apo-B in LDL disappeared. PM2.5 treatment (final 30 ppm) also induced cellular uptake of oxidized LDL (oxLDL) into macrophages, especially in the presence of fructose (final 50 mM). Uptake of oxLDL along with production of reactive oxygen species was accelerated by PM2.5 solution in a dose-dependent manner. Further, PM2.5 solution caused cellular senescence in human dermal fibroblast cells. Microinjection of PM2.5 solution into zebrafish embryos induced severe mortality accompanied by impairment of skeletal development. In conclusion, water extract of PM2.5 induced oxidative stress as a precursor to cardiovascular toxicity, skin cell senescence, and embryonic toxicity via aggregation and proteolytic degradation of serum lipoproteins. PMID:26615830

  13. The vertical distribution of PM2.5 and boundary-layer structure during summer haze in Beijing

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Song, Tao; Tang, Guiqian; Wang, Yuesi

    2013-08-01

    became more significant, while the low temperatures at higher altitudes facilitated the formation of organic aerosols. Sometimes, the PM2.5 levels increased due to long-range transmission of smoke plume into the residual layer. By the synchronous effect of these factors, the moisture absorption of PM2.5 in the upper layer increased, at times resulting in a "higher-top and lower-bottom" pattern of the PM2.5 distribution.

  14. Chemical characterization, the transport pathways and potential sources of PM2.5 in Shanghai: Seasonal variations

    NASA Astrophysics Data System (ADS)

    Zhao, Mengfei; Huang, Zhongsi; Qiao, Ting; Zhang, Yuankai; Xiu, Guangli; Yu, Jianzhen

    2015-05-01

    The 24-h PM2.5 samples were collected at the site of East China University of Science and Technology (ECUST) in Shanghai from 2011 to 2012, representing winter, spring, summer and autumn, respectively. And PM2.5 and its chemical components including organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), humic-like substance carbon (HULIS-C) and water-soluble ions were analyzed. The results suggested that the average PM2.5 concentrations were (70.35 ± 43.75) μg/m3, (69.76 ± 38.67) μg/m3, (51.26 ± 28.25) μg/m3 and (82.37 ± 48.70) μg/m3 in winter, spring, summer and autumn, respectively. Secondary inorganic ions (sulfate, nitrate and ammonium) were the dominant pollutants of PM2.5 in the four seasons. Total carbon (TC) was an important component explaining above 15% of PM2.5. OC/EC ratios were all above 2 ranging from 4.31 to 6.35; particularly in winter it reached the highest 6.35 which demonstrated that secondary organic carbon (SOC) should be a significant composition of PM2.5. The SOC calculated based on the OC/EC ratio method had stronger correlation with WSOC in summer and autumn (summer: R2 = 0.73 and autumn: R2 = 0.75). The HULIS-C and SOC most significantly correlated in autumn (R2 = 0.83). The data showed that PM2.5 atmospheric aerosols were more acidic in autumn and the concentrations of PM2.5 and its chemical components were much higher. Factor analysis (FA), cluster analysis of air mass back trajectories, potential source contribution function (PSCF) model and concentration weighted trajectory (CWT) model were used to investigate the transport pathways and identify potential source areas of PM2.5 in different seasons. FA identified various sources of PM2.5: secondary aerosol reactions, the aged sea salts and road dusts. The results of cluster analysis, PSCF model and CWT model demonstrated that the local sources in the Yangtze River Delta Region (YRDR) made significant contributions to PM2.5. During winter and autumn long-time

  15. RELAP5 assessment: LOFT large break L2-5

    SciTech Connect

    Thompson, S L; Kmetyk, L N

    1984-02-01

    RELAP5 is part of an effort to determine the ability of various systems codes to predict the detailed thermal/hydraulic response of LWRs during accident and off-normal conditions. The RELAP5 code is being assessed at SNLA against test data from various integral and separate effects test facilities. As part of this assessment matrix, a large break transient performed at the LOFT facility has been analyzed. The results show that RELAP5/MOD1 correctly calculates many of the major system variables (i.e., pressure, break flows, peak clad temperature) early in a large break LOCA. The major problems encountered in the analyses were incorrect pump coastdown and loop seal clearing early in the calculation, excessive pump speedup later in the transient (probably due to too much condensation-induced pressure drop at the ECC injection point), and excess ECC bypass calculated throughout the later portions of the test; only the latter problem significantly affected the overall results. This excess ECC bypass through the downcomer and vessel-side break resulted in too-large late-time break flows and high system pressure due to prolonged choked flow conditions. It also resulted in a second core heatup being calculated after the accumulator emptied, since water was not being retained in the vessel. Analogous calculations with a split-downcomer nodalization delivered some ECC water to the lower plenum, which was then swept up the core and upper plenum and out the other (pump-side) break; thus no significant differences in long-term overall behavior were evident between the calculations.

  16. Can MODIS AOD be employed to derive PM2.5 in Beijing-Tianjin-Hebei over China?

    NASA Astrophysics Data System (ADS)

    Ma, Xiaoyan; Wang, Jianying; Yu, Fangqun; Jia, Hailing; Hu, Yanan

    2016-11-01

    The fine particular matter (PM) concentrations in China have increased considerably due to the rapid economic growth and urbanization in the last few decades, especially in the most populated and industrialized regions. Beijing-Tianjin-Hebei is one of the most polluted regions in China, so to monitor the PM2.5 concentrations over this region is quite critical for human health. By making use the new released hourly PM2.5 mass concentration from ground-based observations in Beijing-Tianjin-Hebei over China, and collocated MODIS level 2 AOD data from April 2014 to March 2015, we explored the relation between surface PM2.5 mass concentration and MODIS AOD and possibility to derive the surface PM2.5 from satellite retrieval in the region. Our study show that the relation strongly depend on the seasons due to distinct seasonal characteristics of PM2.5 and AOD, with a relatively better correlation in spring and summertime (correlation coefficient r ranging from 0.52 to 0.79) than autumn and wintertime (r can be low as to 0.23 in site Baoding). Our analysis gave evidence that worse relationship and/or smaller number of sample in wintertime is associated with the significantly high PM2.5 concentration and a lot of missing data occurring in MODIS AOD, implying that current MODIS AOD retrieval scheme does not work very well in highly polluted cases. The derived PM2.5 mass concentration from MODIS AOD in summertime can basically capture the major observed features of the time series and about 20% large bias of the derived values compared to the observation is expected to be reduced if longer time period data is available and used for analysis.

  17. Life after Adolescent and Adult Moderate and Severe Traumatic Brain Injury: Self-Reported Executive, Emotional, and Behavioural Function 2-5 Years after Injury.

    PubMed

    Finnanger, Torun Gangaune; Olsen, Alexander; Skandsen, Toril; Lydersen, Stian; Vik, Anne; Evensen, Kari Anne I; Catroppa, Cathy; Håberg, Asta K; Andersson, Stein; Indredavik, Marit S

    2015-01-01

    Survivors of moderate-severe Traumatic Brain Injury (TBI) are at risk for long-term cognitive, emotional, and behavioural problems. This prospective cohort study investigated self-reported executive, emotional, and behavioural problems in the late chronic phase of moderate and severe TBI, if demographic characteristics (i.e., age, years of education), injury characteristics (Glasgow Coma Scale score, MRI findings such as traumatic axonal injury (TAI), or duration of posttraumatic amnesia), symptoms of depression, or neuropsychological variables in the first year after injury predicted long-term self-reported function. Self-reported executive, emotional, and behavioural functioning were assessed among individuals with moderate and severe TBI (N = 67, age range 15-65 years at time of injury) 2-5 years after TBI, compared to a healthy matched control group (N = 72). Results revealed significantly more attentional, emotional regulation, and psychological difficulties in the TBI group than controls. Demographic and early clinical variables were associated with poorer cognitive and emotional outcome. Fewer years of education and depressive symptoms predicted greater executive dysfunction. Younger age at injury predicted more aggressive and rule-breaking behaviour. TAI and depressive symptoms predicted Internalizing problems and greater executive dysfunction. In conclusion, age, education, TAI, and depression appear to elevate risk for poor long-term outcome, emphasising the need for long-term follow-up of patients presenting with risk factors. PMID:26549936

  18. Final Technical Report. Results of Phases 2-5

    SciTech Connect

    Narang, David; Ayyanar, Raja; Gemin, Paul; Baggu, Murali; Srinivasan, Devarajan

    2015-02-27

    APS’s renewable energy portfolio, driven in part by Arizona’s Renewable Energy Standard (RES) currently includes more than 1100 MW of installed capacity, equating to roughly 3000 GWh of annual production. Overall renewable production is expected to grow to 6000 GWh by 2025. It is expected that distributed photovoltaics, driven primarily by lower cost, will contribute to much of this growth and that by 2025, distributed installations will account for half of all renewable production (3000GHW). As solar penetration increases, additional analysis may be required for routine utility processes to ensure continued safe and reliable operation of the electric distribution network. Such processes include residential or commercial interconnection requests and load shifting during normal feeder operations. Circuits with existing high solar penetration will also have to be studied and results will need to be evaluated for adherence to utility practices or strategy. Increased distributed PV penetration may offer benefits such as load offsetting, but it also has the potential to adversely impact distribution system operation. These effects may be exacerbated by the rapid variability of PV production. Detailed effects of these phenomena in distributed PV applications continue to be studied. Comprehensive, high-resolution electrical models of the distribution system were developed to analyze the impacts of PV on distribution circuit protection systems (including coordination and anti-islanding), predict voltage regulation and phase balance issues, and develop volt/VAr control schemes. Modeling methods were refined by validating against field measurements. To augment the field measurements, methods were developed to synthesize high resolution load and PV generation data to facilitate quasi-static time series simulations. The models were then extended to explore boundary conditions for PV hosting capability of the feeder and to simulate common utility practices such as feeder

  19. Battery condenser system PM2.5 emission factors and rates for cotton gins: Method 201A combination PM10 and PM2.5 sizing cyclones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This report is part of a project to characterize cotton gin emissions from the standpoint of stack sampling. In 2006, EPA finalized and published a more stringent standard for particulate matter with nominal diameter less than or equal to 2.5 µm (PM2.5). This created an urgent need to collect additi...

  20. Equating Semi-Continuous (SC) PM2.5 Mass Monitor Measurement Values with Federal Reference Method (FRM) PM2.5 Monitor Measurement Values

    EPA Science Inventory

    The effects of fine particulate matter (PM2.5) on human health are well documented (Pope et al., 2002). In order to spatially and temporally assess the impact of PM2.5 on the U.S. population, the U.S. Environmental Protection Agency (U.S. EPA) operates a ne...

  1. Personal exposures and microenvironment concentrations of PM 2.5, VOC, NO 2 and CO in Oxford, UK

    NASA Astrophysics Data System (ADS)

    Lai, H. K.; Kendall, M.; Ferrier, H.; Lindup, I.; Alm, S.; Hänninen, O.; Jantunen, M.; Mathys, P.; Colvile, R.; Ashmore, M. R.; Cullinan, P.; Nieuwenhuijsen, M. J.

    Between 1998 and 2000 in Oxford, UK, simultaneous personal exposures and microenvironmental measurements (home indoor, home outdoor and work indoor) to fine particulate matters PM 2.5, volatile organic compounds (VOC), nitrogen dioxide (NO 2) and carbon monoxide (CO) were carried out once per person among 50 adults over a 48-h period. Thirty-seven elements in PM 2.5 and 30 different VOCs were analysed. Questionnaires were distributed to record their time-activity patterns and exposure-related information. Results showed that participants spent more time (89.5%) in all indoors than in other microenvironments. Geometric mean (GM) of personal and home indoor levels of PM 2.5, 14 elements (aluminium, arsenic, bromine, calcium, copper, iron, gallium, potassium, sodium, phosphorus, lead, selenium, silicon, titanium), total VOC (TVOC) and 8 individual compounds (nonane, decane, undecane, trimethylbenzene, toluene, benzaldehyde, alpha-pinene and d-limonene) were over 20% higher than their GM outdoor levels. Those of NO 2, 5 aromatic VOCs (benzene, o-xylene, ethylbenzene, propylbenzene, m, p-xylene) and 5 other elements (chlorine, magnesium, manganese, sulphur, zinc) were close to their GM outdoor levels. For PM 2.5 and TVOC, personal exposures and residential indoor levels (in GM) were about 2 times higher among the tobacco-smoke exposed group compared to the non-smoke exposed group, suggesting that smoking is an important determinant of these exposures. Determinants for CO were visualised by real-time monitoring, and we showed that the peak levels of personal exposure to CO were associated with smoking, cooking and transportation activities. Moderate to good correlations were only found between the personal exposures and residential indoor levels for both PM 2.5 ( r=0.60, p<0.001) and NO 2 ( r=0.47, p=0.003).

  2. TASK 2.5.5 NATURAL EXPOSURE TESTING IN CALIFORNIA

    SciTech Connect

    Miller, William A; Cheng, Mengdawn; New, Joshua Ryan; Ronnen, Levinson; Akbari, Hashem; Berhahl, Paul

    2010-03-01

    Airborne particulate matter that settles on a roof can either reflect or absorb incoming solar radiation, dependent on the chemical content and size of the particles. These light scattering and absorption processes occur within a few microns of the surface, and can affect the solar reflectance of the roof. Wilkes et al. (2000) tested 24 different roof coatings on a low-slope test stand and observed about a 25% decrease in the solar reflectance of white-coated and aluminum-coated surfaces as the time of exposure increased; however, the decrease leveled off after 2 years. SPRI Inc. and its affiliates studied the effect of climatic exposure on the surface properties of white thermoplastic single-ply membranes and determined that membranes lose from 30 to 50% of their reflectance over 3 years (Miller et al. 2002). The CMRC and its affiliates AISI, NamZAC, MBMA, MCA and NCCA exposed unpainted and painted metal roofing on both steep- and low-slope test roofs and found that after 3 years, the painted polyvinylidene fluoride (PVDF) metal roofs lost less than 5% of their original reflectance (Miller et al. 2004). The results of the three different weathering studies are very interesting in terms of their solar reflectance after 3 years of exposure. The white thermoplastic membrane and white ceramic coating with white topcoat had original reflectance measures that were about 20 percentage points higher than the painted metal; however, after 3-years of field exposure the solar reflectance of the painted metal exceeds that of the thermoplastic membrane and equals that of the coating. The long-term loss of reflectance appears driven by the ability of the particulate matter to cling to the roof and resist being washed off by wind and or rain. Miller et al. (2002) discovered that aerosol deposition introduced biomass of complex microbial consortia onto the test roofs and the combination of contaminants and biomass accelerated the loss of solar reflectance for the thermoplastic

  3. Successful treatment of capture myopathy in three wild greater sandhill cranes (Grus canadensis tabida).

    PubMed

    Businga, Nancy K; Langenberg, Julie; Carlson, LaVinda

    2007-12-01

    Two adult and 1 juvenile free-flying greater sandhill cranes (Grus canadensis tabida) were diagnosed with capture myopathy after alpha-chloralose baiting and physical capture during a banding and feeding ecologic study. Blood samples were collected for serum biochemical analysis at the time of capture for the 2 adults, and at 24 hours postcapture, at various intervals during treatment, and at the time of release for all 3 birds. Concentrations of creatine kinase, aspartate transaminase, and lactate dehydrogenase were high within 1 hour of capture and peaked approximately 3 days after capture. By days 10-17 after capture, creatine kinase and lactate dehydrogenase concentrations both decreased to within the reference range measured for cranes at capture, but aspartate transaminase concentrations remained 2-5 times higher than the measured reference range. Treatment consisted of corticosteroids, selenium/vitamin E, parenteral fluids, and gavage feedings. Physical therapy consisted of assisting the cranes to stand and walk 2-8 times a day, massaging leg muscles, and moving limbs manually through the range of motion. The adults were released when they were able to stand up independently and were pacing in the pen. The juvenile was released 12 hours after it was able to stand independently but was returned to the pen when it fell and could not rise. It was treated supportively for an additional 3 days and then successfully released. Both adult cranes were observed on their territories with their original mates after release and returned to their territories for the subsequent 8 years, raising chicks most years. After release, the juvenile was observed in a flock of cranes near its natal territory for the next 2 days.

  4. MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE (PM 10-2.5) CONCENTRATIONS: AUGUST 2005 UPDATED REPORT REGARDING SECOND-GENERATION AND NEW PM 10-2.5 SAMPLERS

    EPA Science Inventory

    Multi-site field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 (PM10 2.5) in ambient air. The field studies involved the use of both time-integrated filter-based and direct continuous methods. Despite operationa...

  5. Effects of day-of-week trends and vehicle types on PM2.5-bounded carbonaceous compositions.

    PubMed

    Pongpiachan, Siwatt; Kositanont, Charnwit; Palakun, Jittree; Liu, Suixin; Ho, Kin Fai; Cao, Junji

    2015-11-01

    Carbonaceous compositions of PM2.5 were measured in the heart of Bangkok from 17th November 2010 to 19th January 2012, and a data set of 94 samples was constructed. Effects of day-of-week trends and vehicle types on PM2.5-bound TC, OC, and EC were carefully investigated. In this study, OC was the most important contributor to the total PM2.5 mass concentration. The average PM2.5-bound OC content measured at CHAOS (18.8 ± 9.18 μg m(-3)) was approximately 11 times higher than at Chaumont, Switzerland (1.7 μg m(-3)), but approximately five times lower than at Xi'an, China (93.0 μg m(-3)). The application of diagnostic binary ratios of OC/EC and estimations of secondary organic carbon (SOC) coupled with autocorrelation plots (Box and Jenkins) highlight the enhanced impacts of traffic emissions, especially from diesel vehicles, on PM2.5-bound carbonaceous compositions on weekdays relative to weekends. Hierarchical cluster analysis (HCA) coupled with principal component analysis (PCA) underline the importance of diesel emissions as the primary contributors of carbonaceous aerosols, particularly during weekdays. PMID:26100727

  6. Changing Water Environment in the Greater Jakarta Basins

    NASA Astrophysics Data System (ADS)

    Pawitan, H.; Delinom, R.; Lubis, R. F.

    2014-12-01

    Recent rapid economic development in the greater Jakarta areas has caused not only increased water resources demands but also affects the water environment due to population increase and land use changes, that further causes land degradation, and changes in hydrologic regimes and environmental qualities. In the present study, the water environmental capacities as indicated by the changing landscapes in the greater Jakarta basins were investigated to understand the role of land use management and its impact on water resources, ecosystem and environmental services. The Ciliwung river basin where rapid population increases and progresses of the land use/cover changes occurring was selected as a representative basin, and 41 water samplings were taken at different time of Jan. 08, Apr. 08, Jul. 08, and Oct. 08 during 2009 to understand the effect of rainfall variation on water quality, and clarify the characteristics of hydrological cycle. Landuse changes of the upper basins as can be seen for the upper basin indicated the expansion of settlements during 1990 to 2004 from 4.1% to 17.6% or in acreage increased almost five times, not only converting forested area, but mostly taking place from paddy fields that contributed about 50% of the additional land for new settlements. Urbanization expanding around the greater Jakarta basins, is closely related to the increased fluctuations of river discharges in recent years, with recurrence floods quickly after heavy rainfall events. Furthermore, the study results indicated that water quality of Ciliwung river, especially the loading concentrations of nitric acid closely reflects the population densities of the watershed. These results suggest that the land use/cover changes of the greater Jakarta basins affect largely the change of water environment of the areas and resulting a deteriorated factor for water resources, ecosystems and environmental services in both of quantity and quality

  7. Transported vs. local contributions from secondary and biomass burning sources to PM2.5

    NASA Astrophysics Data System (ADS)

    Kim, Bong Mann; Seo, Jihoon; Kim, Jin Young; Lee, Ji Yi; Kim, Yumi

    2016-11-01

    The concentration of fine particulates in Seoul, Korea has been lowered over the past 10 years, as a result of the city's efforts in implementing environmental control measures. Yet, the particulate concentration level in Seoul remains high as compared to other urban areas globally. In order to further improve fine particulate air quality in the Korea region and design a more effective control strategy, enhanced understanding of the sources and contribution of fine particulates along with their chemical compositions is necessary. In turn, relative contributions from local and transported sources on Seoul need to be established, as this city is particularly influenced by sources from upwind geographic areas. In this study, PM2.5 monitoring was conducted in Seoul from October 2012 to September 2013. PM2.5 mass concentrations, ions, metals, organic carbon (OC), elemental carbon (EC), water soluble OC (WSOC), humic-like substances of carbon (HULIS-C), and 85 organic compounds were chemically analyzed. The multivariate receptor model SMP was applied to the PM2.5 data, which then identified nine sources and estimated their source compositions as well as source contributions. Prior studies have identified and quantified the transported and local sources. However, no prior studies have distinguished contributions of an individual source between transported contribution and locally produced contribution. We differentiated transported secondary and biomass burning sources from the locally produced secondary and biomass burning sources, which was supported with potential source contribution function (PSCF) analysis. Of the total secondary source contribution, 32% was attributed to transported secondary sources, and 68% was attributed to locally formed secondary sources. Meanwhile, the contribution from the transported biomass burning source was revealed as 59% of the total biomass burning contribution, which was 1.5 times higher than that of the local biomass burning source

  8. Ultrafine particles, and PM 2.5 generated from cooking in homes

    NASA Astrophysics Data System (ADS)

    Wan, Man-Pun; Wu, Chi-Li; Sze To, Gin-Nam; Chan, Tsz-Chun; Chao, Christopher Y. H.

    2011-11-01

    Exposure to airborne particulate matters (PM) emitted during cooking can lead to adverse health effects. An understanding of the exposure to PM during cooking at home provides a foundation for the quantification of possible health risks. The concentrations of airborne particles covering the ultrafine (14.6-100 nm) and accumulation mode (100-661.2 nm) size ranges and PM 2.5 (airborne particulate matters smaller than 2.5 μm in diameter) during and after cooking activities were measured in 12 naturally ventilated, non-smoking homes in Hong Kong, covering a total of 33 cooking episodes. The monitored homes all practiced Chinese-style cooking. Cooking elevated the average number concentrations of ultrafine particles (UFPs) and accumulation mode particles (AMPs) by 10 fold from the background level in the living room and by 20-40 fold in the kitchen. PM 2.5 mass concentrations went up to the maximum average of about 160 μg m -3 in the kitchen and about 60 μg m -3 in the living room. Cooking emitted particles dispersed quickly from the kitchen to the living room indicating that the health impact is not limited to occupants in the kitchen. Particle number and mass concentrations remained elevated for 90 min in the kitchen and for 60 min in the living room after cooking. Particles in cooking emissions were mainly in the ultrafine size range in terms of the number count while AMPs contributed to at least 60% of the surface area concentrations in the kitchen and 73% in the living room. This suggests that AMPs could still be a major health concern since the particle surface area concentration is suggested to have a more direct relationship with inhalation toxicity than with number concentration. Particle number concentration (14.6-661.2 nm) in the living room was about 2.7 times that in the outdoor environment, suggesting that better ventilation could help reduce exposure.

  9. Polar organic tracers in PM2.5 aerosols from forests in eastern China

    NASA Astrophysics Data System (ADS)

    Wang, W.; Wu, M. H.; Li, L.; Zhang, T.; Liu, X. D.; Feng, J. L.; Li, H. J.; Wang, Y. J.; Sheng, G. Y.; Claeys, M.; Fu, J. M.

    2008-12-01

    Photooxidation products of biogenic volatile organic compounds, mainly isoprene and monoterpenes, are significant sources of atmospheric particulate matter in forested regions. The objectives of this study were to examine time series and diel variations of polar organic tracers for the photooxidation of isoprene and α-pinene to investigate whether they are linked with meteorological parameters or trace gases, and to determine their carbon contributions. In addition, the biogenic secondary organic carbon contributions from isoprene were estimated. PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) aerosol samples were collected from forests in eastern China and compared with data from forested sites in Europe and America. Aerosol sampling was conducted at four sites located along a gradient of ecological succession in four different regions, i.e. Changbai Mountain Nature Reserve (boreal-temperate), Chongming National Forest Park (temperate), Dinghu Mountain Nature Reserve (subtropical) and Jianfengling Nature Reserve in Hainan (tropical) during summer periods when the meteorological conditions are believed to be favorable for photochemical processes. Fifty PM2.5 samples were collected; eighteen organic compounds, organic carbon (OC), elemental carbon and trace gases were measured. Results indicate that the concentration trends of the secondary organic compounds reflected those of the trace gases and meteorological parameters. Very good correlations between the sum concentrations of isoprene oxidation products and atmospheric SO2, O3, NO2, NOx, as well as CO2, at the Changbai site were found. The secondary OC due to isoprene was relatively high in tropical Hainan (0.27 μgC/m3) where isoprene-emitting broadleaf species are dominant, but was comparable in boreal Changbai (0.32 μgC/m3) where coniferous species are prevalent. The contribution of malic acid, which may have both biogenic and anthropogenic sources, to the OC mass was comparable at the four

  10. Photometrically measured continuous personal PM(2.5) exposure: levels and correlation to a gravimetric method.

    PubMed

    Lanki, Timo; Alm, Sari; Ruuskanen, Juhani; Janssen, Nicole A H; Jantunen, Matti; Pekkanen, Juha

    2002-05-01

    There is evidence that hourly variations in exposure to airborne particulate matter (PM) may be associated with adverse health effects. Still there are only few published data on short-term levels of personal exposure to PM in community settings. The objectives of the study were to assess hourly and shorter-term variations in personal PM(2.5) exposure in Helsinki, Finland, and to compare results from portable photometers to simultaneously measured gravimetric concentrations. The effect of relative humidity on the photometric results was also evaluated. Personal PM(2.5) exposures of elderly persons were assessed for 24 h every second week, resulting in 308 successful measurements from 47 different subjects. Large changes in concentrations in minutes after cooking or changing microenvironment were seen. The median of daily 1-h maxima was over twice the median of 24-h averages. There was a strong significant association between the two means, which was not linear. Median (95th percentile) of the photometric 24-h concentrations was 12.1 (37.7) and of the 24-h gravimetric concentrations 9.2 (21.3) microg/m3. The correlation between the photometric and the gravimetric method was quite good (R2=0.86). Participants spent 94.1% of their time indoors or in a vehicle, where relative humidity is usually low and thus not likely to cause significant effects on photometric results. Even outdoors, the relative humidity had only modest effect on concentrations. Photometers are a promising method to explore the health effects of short-term variation in personal PM(2.5) exposure.

  11. Compositional characterization of PM 2.5 emitted from in-use diesel vehicles

    NASA Astrophysics Data System (ADS)

    Kim Oanh, Nguyen Thi; Thiansathit, Worrarat; Bond, Tami C.; Subramanian, R.; Winijkul, Ekbordin; Paw-armart, Ittipol

    2010-01-01

    In Asian developing countries diesel vehicles contribute significantly to urban air pollution. The emission factors (EF) and exhaust gas composition of these vehicles may be different from those in the US and Europe, where most emission measurements are taken. This study focuses on the fine particulate matter (PM 2.5) emission from in-use diesel vehicles in Bangkok, with the goal of providing EF and source profiles that are more appropriate for developing countries. The chassis dynamometer test results for 93 vehicles, including 39 light duty (LD) and 54 heavy duty (HD) of the age models between 1972 and 2005, are presented. PM EF are lower for vehicles of newer year models, consistent with the implementation of engine standards. The average PM 2.5 EF of 0.23 g km -1 for LD, and 1.76 g km -1 for HD trucks and buses are generally higher than the literature reported values. Old HD trucks produce the highest PM EF of above 3 g km -1. Black carbon (BC), measured by an optical method, is well correlated with elemental carbon (EC) by TOT, but is consistently about 1.7 times higher. Between the LD and HD fleets, there is no significant difference in the fractional composition (BC, EC, OC, water soluble ions and elements) of emitted PM 2.5. The composite source profile, weighted against the fleet composition and the vehicle km travelled (VKT) for the city has an average OC of 19%, EC of 47%, and sulfate of 2%, which are close to those reported for 1980s US diesel vehicles.

  12. Mechanisms of in vitro pyrrole adduct autoxidation in 2,5-hexanedione-treated protein.

    PubMed

    DeCaprio, A P

    1986-11-01

    The neurotoxic gamma-diketone, 2,5-hexanedione, reacts with axonal protein amine residues to form 2,5-dimethylpyrrole adducts. Current evidence implicates this reaction as the potentially critical step in gamma-diketone neurotoxicity, although it is unclear whether pyrrole formation per se is sufficient to induce neuropathy or whether secondary autoxidative reactions are also required. The present in vitro study examines aspects of pyrrole formation and the secondary phenomena of chromophore development and covalent protein crosslinking in 2,5-hexanedione-treated protein. p-Dimethylaminobenzaldehyde (DMAB)-detectable pyrrole concentrations decreased linearly with time when pyrrolylated bovine serum albumin (pyrrole-BSA) was incubated under air, but remained unchanged following N2 incubation. The air-induced decrease was accompanied by the appearance of chromophores and crosslinked protein. Covalent crosslinking of pyrrole-BSA was pH-dependent, with relatively increased intermolecular bridging at pH 7.4 as compared to pH 9.5. Chromophore formation and the loss in DMAB-detectable pyrrole were also accelerated at the lower pH. Autoxidative parameters were inhibited in the presence of a free radical scavenger (ascorbic acid) but induced by free radical initiators (potassium persulfate and 2,2'-azobis[2-amidinopropane hydrochloride]). In vitro incubation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of combinations of bovine serum albumin, ribonuclease, pyrrole-BSA, and pyrrolylated ribonuclease revealed that the intermolecular crosslinking pathway was mediated by pyrrole-pyrrole bridging. These findings demonstrate that the secondary autoxidative phenomena following pyrrole adduct formation in gamma-diketone-treated protein proceed via pH-dependent, free radical-mediated mechanisms. If similar mechanisms are present in vivo, the results also suggest that intermolecular covalent crosslinking of pyrrolylated axonal protein may be less widespread

  13. Statistical analysis of PM2.5 observations from diplomatic facilities in China

    NASA Astrophysics Data System (ADS)

    San Martini, Federico M.; Hasenkopf, Christa A.; Roberts, David C.

    2015-06-01

    Systematic monitoring of air quality are lacking in many parts of the world, especially in cities where air quality is poor. Since 2008, the U.S. Embassy in Beijing has been collecting real-time air-quality data from a monitor on the Embassy's rooftop and sharing that data publicly through social media. Using this freely available data, as well as those from four other U.S. consulates in China that are also now collecting and sharing data publicly, we demonstrate that rooftop air-quality monitors installed at embassies and consulates can further our understanding of air quality and provide a rich, hourly-averaged, long-term data source for the academic community and decision-makers. For example, this is the first study to present an analysis of diurnal variability of PM2.5 in Chengdu, Guangzhou, Shanghai, and Shenyang. We analyzed the diurnal variability of PM2.5 over the entire period of measurement for those cities and Beijing, and found marked variation across seasons and between cities. This dataset allows comparison of the PM2.5 annual average concentrations in 2013, with Guangzhou reporting 56.3 μg/m3, Shanghai 61.6 μg/m3, Chengdu 96.1 μg/m3, Beijing 99.6 μg/m3, and Shenyang 76.3 μg/m3 (note the average in Shenyang is from August 2013-July 2014). This study demonstrates the potential uses of air quality data that is currently systematically being collected and made publicly accessible by U.S. embassies and consulates in polluted but under-studied locations.

  14. Television viewing through ages 2-5 years and bullying involvement in early elementary school

    PubMed Central

    2014-01-01

    Background High television exposure time at young age has been described as a potential risk factor for developing behavioral problems. However, less is known about the effects of preschool television on subsequent bullying involvement. We examined the association between television viewing time through ages 2-5 and bullying involvement in the first grades of elementary school. We hypothesized that high television exposure increases the risk of bullying involvement. Method TV viewing time was assessed repeatedly in early childhood using parental report. To combine these repeated assessments we used latent class analysis. Four exposure classes were identified and labeled “low”, “mid-low”, “mid-high” and “high”. Bullying involvement was assessed by teacher questionnaire (n = 3423, mean age 6.8 years). Additionally, peer/self-report of bullying involvement was obtained using a peer nomination procedure (n = 1176, mean age 7.6 years). We examined child risk of being a bully, victim or a bully-victim (compared to being uninvolved in bullying). Results High television exposure class was associated with elevated risks of bullying and victimization. Also, in both teacher- and child-reported data, children in the high television exposure class were more likely to be a bully-victim (OR = 2.11, 95% CI: 1.42-3.13 and OR = 3.68, 95% CI: 1.75-7.74 respectively). However, all univariate effect estimates attenuated and were no longer statistically significant once adjusted for maternal and child covariates. Conclusions The association between television viewing time through ages 2-5 and bullying involvement in early elementary school is confounded by maternal and child socio-demographic characteristics. PMID:24520886

  15. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....5 precursors. For purposes of defining the data elements for these inventories, the PM2.5 and PM2.5 precursor-relevant data element requirements under subpart A of this part shall apply. (2) Submit...

  16. EVALUATION OF SEVERAL PM 2.5 FORECAST MODELS USING DATA COLLECTED DURING THE ICARTT/NEAQS 2004 FIELD STUDY

    EPA Science Inventory

    Real-time forecasts of PM2.5 aerosol mass from seven air-quality forecast models (AQFMs) are statistically evaluated against observations collected in the northeastern U.S. and southeastern Canada from two surface networks and aircraft data during the summer of 2004 IC...

  17. Dust monitoring on the Hanford Site: An investigation into the relationship between TSP, PM-10 and PM-2.5

    SciTech Connect

    Schwartz, Tara L.; Fritz, Brad G.

    2004-12-01

    Samples were collected to determine TSP concentration in air on the central plateau of the Hanford Site. These were compared to PM-10 and PM-2.5 data collected over the same time period. Results provide a means to estimate TSP concentration based on PM-10 concentration.

  18. Residential indoor PM2.5 in wood stove homes: follow-up of the Libby changeout program

    PubMed Central

    Noonan, Curtis W.; Navidi, William; Sheppard, Lianne; Palmer, Christopher P.; Bergauff, Megan; Hooper, Kathi; Ward, Tony J.

    2012-01-01

    In 2005 through 2008 a small rural mountain valley community engaged in a wood stove changeout program to address concerns of poor ambient air quality. During this program we assessed changes to indoor air quality before and after the introduction of a new, lower emission wood stove. We previously reported a greater than 70% reduction in indoor PM2.5 concentrations in homes following the installation of a new EPA-certified stove within the home. We report here on follow-up of the experiences in these and other homes over three winters of sample collection. In 21 homes, we compared pre-changeout PM2.5 concentrations (mean (sd) = 45.0 (33.0) μg/m3) to multiple post-changeout measures of PM2.5 concentrations using a DustTrak. The mean reduction (and 95% confidence interval) from pre-changeout to post-changeout was −18.5 μg/m3 (−31.9, −5.2), adjusting for ambient PM2.5, ambient temperature, and other factors. Findings across homes and across years were highly variable, and a subset of homes did not experience a reduction in PM2.5 following changeout. Reductions were also observed for organic carbon, elemental carbon, and levoglucosan, but increases were observed for dehydroabietic acid and abietic acid. Despite overall improvements in indoor air quality, the varied response across homes may be due to factors other than the introduction of a new wood stove. PMID:22607315

  19. Trends in arsenic levels in PM10 and PM 2.5 aerosol fractions in an industrialized area.

    PubMed

    García-Aleix, J R; Delgado-Saborit, J M; Verdú-Martín, G; Amigó-Descarrega, J M; Esteve-Cano, V

    2014-01-01

    Arsenic is a toxic element that affects human health and is widely distributed in the environment. In the area of study, the main Spanish and second largest European industrial ceramic cluster, the main source of arsenic aerosol is related to the impurities in some boracic minerals used in the ceramic process. Epidemiological studies on cancer occurrence in Spain points out the study region as one with the greater risk of cancer. Concentrations of particulate matter and arsenic content in PM10 and PM2.5 were measured and characterized by ICP-MS in the area of study during the years 2005-2010. Concentrations of PM10 and its arsenic content range from 27 to 46 μg/m(3) and from 0.7 to 6 ng/m(3) in the industrial area, respectively, and from 25 to 40 μg/m(3) and from 0.7 to 2.8 ng/m(3) in the urban area, respectively. Concentrations of PM2.5 and its arsenic content range from 12 to 14 μg/m(3) and from 0.5 to 1.4 ng/m(3) in the urban background area, respectively. Most of the arsenic content is present in the fine fraction, with ratios of PM2.5/PM10 in the range of 0.65-0.87. PM10, PM2.5, and its arsenic content show a sharp decrease in recent years associated with the economic downturn, which severely hit the production of ceramic materials in the area under study. The sharp production decrease due to the economic crisis combined with several technological improvements in recent years such as substitution of boron, which contains As impurities as raw material, have reduced the concentrations of PM10, PM2.5, and As in air to an extent that currently meets the existing European regulations.

  20. A quantitative analysis of grid nudging effect on each process of PM2.5 production in the Korean Peninsula

    NASA Astrophysics Data System (ADS)

    Jeon, Wonbae; Choi, Yunsoo; Lee, Hwa Woon; Lee, Soon-Hwan; Yoo, Jung-Woo; Park, Jaehyeong; Lee, Hyo-Jung

    2015-12-01

    This study investigated the effect of assimilated meteorological fields on simulated PM2.5 concentrations in the Korean Peninsula. Two different CMAQ simulations were conducted using base WRF run (BASE) and grid-nudged WRF run (GNG) which included a simple data assimilation method for the time period of April, 2009. The simulated PM2.5 and PM10 concentrations were compared with corresponding observations. The BASE PM2.5 concentrations were significantly underestimated at Anmyeondo (AMD) and six Air Quality Monitoring Station (AQMS) sites in Korea, but GNG showed improved agreement with in-situ measurements due to the effect of grid nudging. The grid nudging effect was dominant under the PBL height and it appeared more clearly under the unstable synoptic condition (April 5-8) than stable condition (April 9-13). Additional quantitative analysis was conducted using the Integrated Process Rate (IPR) in the CMAQ model to investigate the effect of varied meteorological fields on each PM2.5 production and destruction processes. The PM2.5 production rate by aerosol process in GNG was shown to be higher than that of BASE, especially near the source region (e.g., Eastern China). The increased temperature and decreased wind speed by grid nudging effect led to increase of aerosol production rates especially during the nighttime. The change of aerosol production rates were mainly caused by increased sulfate (SO42-) and nitrate (NO3-) production rates in the day and nighttime respectively. Also, GNG provides higher PM2.5 transport rates than BASE over the whole domain. The amount of PM2.5 scavenged by wet deposition process in GNG was smaller than that of BASE over the Yellow Sea, reflecting the decreased water vapor mixing ratio by grid nudging. Thus, it resulted in the increase of simulated PM2.5 concentrations. The results indicated that understanding the effects of grid nudging on PM2.5 concentrations is crucial to enhance the performance of PM2.5 modeling

  1. Does Unemployment Lead to Greater Alcohol Consumption?

    PubMed

    Popovici, Ioana; French, Michael T

    2013-04-01

    Using panel data from Waves 1 and 2 of the NESARC, we estimate gender-specific effects of changes in employment status on overall alcohol consumption, binge drinking episodes, and a diagnosis of alcohol abuse and/or dependence. We employ various fixed-effects models to address potential bias from unobserved and time-invariant individual heterogeneity. All results show a positive and significant effect of unemployment on drinking behaviors and the findings are robust to numerous sensitivity tests. Perhaps macroeconomic policy decisions intended to stimulate the economy during economic downturns should also consider the avoided personal costs and externalities associated with alcohol misuse.

  2. Promoting greater Federal energy productivity [Final report

    SciTech Connect

    Hopkins, Mark; Dudich, Luther

    2003-03-05

    This document is a close-out report describing the work done under this DOE grant to improve Federal Energy Productivity. Over the four years covered in this document, the Alliance To Save Energy conducted liaison with the private sector through our Federal Energy Productivity Task Force. In this time, the Alliance held several successful workshops on the uses of metering in Federal facilities and other meetings. We also conducted significant research on energy efficiency, financing, facilitated studies of potential energy savings in energy intensive agencies, and undertook other tasks outlined in this report.

  3. Rock Art of the Greater Southwest

    NASA Astrophysics Data System (ADS)

    Krupp, Edwin C.

    Archaeoastronomical studies in the American Southwest began in 1955 with recognition of what seemed to be pictorial eyewitness records of the Crab supernova of 1054 AD In time, reports of seasonally significant light-and-shadow effects on rock art and associations of rock art with astronomical alignments also emerged. Most astronomical rock art studies remained problematic, however, because criteria for proof of ancient intent were elusive. Disciplined methods for assessing cultural function were difficult to develop, but review of ethnographically documented astronomical traditions of California Indians and of Indians in the American Southwest subsequently increased confidence in the value of some astronomical rock art initiatives.

  4. STRUCTURE OF PRIMARY PM2.5 DERIVED FROM DIESEL TRUCK EXHAUST

    EPA Science Inventory

    The U.S. Environmental Protection Agency is currently considering regulations on airborne particulate matter < 2.5 microns in mean diameter (PM2.5). It is important that the molecular structure and microstructure of PM2.5 from various sources be thoroughly characterized in order ...

  5. A FUNCTIONAL GROUP CHARACTERIZATION OF ORGANIC PM 2.5 EXPOSURE: RESULTS FROM THE RIOPA STUDY

    EPA Science Inventory

    The functional group (FG) composition of urban residential outdoor, indoor, and personal fine particle (PM2.5) samples is presented and used to provide insights relevant to organic PM2.5 exposure. PM2.5 samples (48 h) were collected during the Rel...

  6. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  7. 40 CFR 52.379 - Control strategy: PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (PM2.5) transportation conformity emission budgets for the Connecticut portion of the New York-Northern New Jersey-Long Island, NY-NJ-CT PM2.5 nonattainment area. The April 17, 2007 revision establishes PM2... the New York-Northern New Jersey-Long Island, NY-NJ-CT PM2.5 nonattainment area. (b) Determination...

  8. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  9. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  10. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  11. 10 CFR 960.3-2-2-5 - Formal site nomination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Formal site nomination. 960.3-2-2-5 Section 960.3-2-2-5 Energy DEPARTMENT OF ENERGY GENERAL GUIDELINES FOR THE PRELIMINARY SCREENING OF POTENTIAL SITES FOR A NUCLEAR WASTE REPOSITORY Implementation Guidelines § 960.3-2-2-5 Formal site nomination. After the...

  12. Emissions Inventory of PM2.5 Trace Elements across the United States

    EPA Science Inventory

    This paper presents the first National Emissions Inventory (NEI) of fine particulate matter (PM2.5) that includes the full suite of PM2.5 trace elements (atomic number >10) measured at ambient monitoring sites across the U.S. PM 2.5 emissions in ...

  13. AN OVERVIEW OF PM2.5 SOURCES AND CONTROL STRATEGIES

    EPA Science Inventory

    The new national ambient air quality standard for particulate matter is summarized, with emphasis on fine particles, or PM2.5 (particulate matter with aerodynamic diameter less than 2.5 micrometers). Sources of ambient and indoor PM2.5 are summarized, followed by an overview of c...

  14. 7 CFR 2.5 - Order in which officers of the Department shall act as Secretary.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Order in which officers of the Department shall act as Secretary. 2.5 Section 2.5 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY BY THE SECRETARY OF AGRICULTURE AND GENERAL OFFICERS OF THE DEPARTMENT General § 2.5 Order in...

  15. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  16. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  17. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  18. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  19. 9 CFR 2.5 - Duration of license and termination of license.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Duration of license and termination of license. 2.5 Section 2.5 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Licensing § 2.5 Duration of license and termination...

  20. 43 CFR 8365.2-5 - Public health, safety and comfort.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 2 2011-10-01 2011-10-01 false Public health, safety and comfort. 8365.2-5 Section 8365.2-5 Public Lands: Interior Regulations Relating to Public Lands (Continued) BUREAU OF... § 8365.2-5 Public health, safety and comfort. On developed recreation sites and areas, unless...

  1. Temporal and Spatial Variations in PM2.5 and PM10-2.5 in the Seoul Metropolitan Area between 2002 and 2008

    NASA Astrophysics Data System (ADS)

    Ghim, Y.; Jung, K.; Kang, M.

    2010-12-01

    Particulate matter (PM; PM10 and PM2.5) concentrations at ambient air monitoring stations located in Seoul between 2002 and 2008 were analyzed. In Korea, PM10 is regulated as a criteria pollutant and thus is monitored as a part of the urban ambient air pollution monitoring network. PM2.5 is currently not a criteria pollutant but will be soon designated as a criteria pollutant. The hourly-average PM10 and PM2.5 samples were collected using the beta-ray absorption method. In this study, data from 14 stations with consistent measurements during the study period were used. As in other major cities, primary factors determining the PM concentrations in Seoul are vehicle emissions (including emissions from other combustion sources) and secondary formation. However, in Seoul, fugitive dust comprising crustal elements accounts for a large proportion of total PM, especially coarse particles (PM10-2.5). During the past several years, the Korean Government as well as the City Government has strived to lessen the PM pollution in Seoul and its satellite cities. Temporal and spatial variations in fine particles (PM2.5) and coarse particles (PM10-2.5) were analyzed to discern behaviors according to the particle size of fugitive dust. Variations in annual averages were examined to assess the effects of policy on PM levels. The influence of fugitive dust was found to be high in the springtime due to low relative humidity and high wind speed, even excluding the Asian dust events. In contrast, PM levels are affected primarily by combustion-related emissions in winter and active secondary formation in later spring and fall. Typical seasonal characteristics and diurnal variations were also explored based on data for high PM2.5 days only. Spatial variability of PM and PM10-2.5 were examined on both all and high PM2.5 days and compared with those of other pollutants.

  2. Collocated comparisons of continuous and filter-based PM2.5 measurements at Fort McMurray, Alberta, Canada

    PubMed Central

    Hsu, Yu-Mei; Wang, Xiaoliang; Chow, Judith C.; Watson, John G.; Percy, Kevin E.

    2016-01-01

    ABSTRACT Collocated comparisons for three PM2.5 monitors were conducted from June 2011 to May 2013 at an air monitoring station in the residential area of Fort McMurray, Alberta, Canada, a city located in the Athabasca Oil Sands Region. Extremely cold winters (down to approximately −40°C) coupled with low PM2.5 concentrations present a challenge for continuous measurements. Both the tapered element oscillating microbalance (TEOM), operated at 40°C (i.e., TEOM40), and Synchronized Hybrid Ambient Real-time Particulate (SHARP, a Federal Equivalent Method [FEM]), were compared with a Partisol PM2.5 U.S. Federal Reference Method (FRM) sampler. While hourly TEOM40 PM2.5 were consistently ~20–50% lower than that of SHARP, no statistically significant differences were found between the 24-hr averages for FRM and SHARP. Orthogonal regression (OR) equations derived from FRM and TEOM40 were used to adjust the TEOM40 (i.e., TEOMadj) and improve its agreement with FRM, particularly for the cold season. The 12-year-long hourly TEOMadj measurements from 1999 to 2011 based on the OR equations between SHARP and TEOM40 were derived from the 2-year (2011–2013) collocated measurements. The trend analysis combining both TEOMadj and SHARP measurements showed a statistically significant decrease in PM2.5 concentrations with a seasonal slope of −0.15 μg m−3 yr−1 from 1999 to 2014.Implications: Consistency in PM2.5 measurements are needed for trend analysis. Collocated comparison among the three PM2.5 monitors demonstrated the difference between FRM and TEOM, as well as between SHARP and TEOM. The orthogonal regressions equations can be applied to correct historical TEOM data to examine long-term trends within the network. PMID:26727574

  3. PM2.5 analog forecast and Kalman filter post-processing for the Community Multiscale Air Quality (CMAQ) model

    NASA Astrophysics Data System (ADS)

    Djalalova, Irina; Delle Monache, Luca; Wilczak, James

    2015-10-01

    A new post-processing method for surface particulate matter (PM2.5) predictions from the National Oceanic and Atmospheric Administration (NOAA) developmental air quality forecasting system using the Community Multiscale Air Quality (CMAQ) model is described. It includes three main components: A real-time quality control procedure for surface PM2.5 observations; Model post-processing at each observational site using historical forecast analogs and Kalman filtering; Spreading the forecast corrections from the observation locations to the entire gridded domain.

  4. One-pot, one-step, catalytic synthesis of 2,5-diformylfuran from fructose

    NASA Astrophysics Data System (ADS)

    Tao, Furong; Cui, Yuezhi; Yang, Pengfei; Gong, Yinghua

    2014-07-01

    MIL-101, a chromium-based metal-organic framework, is known for its very large pore size, large surface area and good stability. However, application of this material in catalysis is still limited. In this paper, a simple and practical catalytic method for the preparation 2,5-diformylfuran (DFF) directly from fructose was investigated. 5% Pd-V(3: 2)@MIL-101 was evaluated as a potential and effective catalyst for the direct oxidation of fructose. The amount of the catalyst, reaction time and temperature had a large effect on the reaction. At the optimized reaction conditions, when the reaction was conducted at 140°C for 600 min, 1 atm oxygen pressure, the yield of DFF reached 34%, fructose conversion was up to 100%. In our system, the main side products were 5-formyl-2-furancarboxylic acid (FFCA) and 2,5-furandicarboxylic acid (FDCA), which are the products of deep oxidation of DFF. This simple and effective catalytic system may be valuable to facilitate energy-efficient conversion of fructose into biofuels and platform chemicals.

  5. CAQI Common Air Quality Index--update with PM(2.5) and sensitivity analysis.

    PubMed

    van den Elshout, Sef; Léger, Karine; Heich, Hermann

    2014-08-01

    The CAQI or Common Air Quality Index was proposed to facilitate the comparison of air quality in European cities in real-time. There are many air quality indices in use in the world. All are somewhat different in concept and presentation and comparing air quality presentations of cities on the internet was virtually impossible. The CAQI and the accompanying website www.airqualitynow.eu and app were proposed to overcome this problem in Europe. This paper describes the logic of making an index, in particular the CAQI and its update with a grid for PM2.5. To assure a smooth transition to the new calculation scheme we studied the behaviour of the index before and after the changes. We used 2006 Airbase data from 31 urban background and 27 street stations all across Europe (that were monitoring PM2.5 in 2006). The CAQI characterises a city by a roadside and urban background situation. It also insists on a minimum number of pollutants to be included in the calculation. Both were deemed necessary to improve the basis for comparing one city to another. A sensitivity analysis demonstrates the comparative behaviour of the street and urban background stations and presents the sensitivity of the CAQI outcome to the pollutants included in its calculation. PMID:24238948

  6. Nonlinear optical behavior of Li n F (n = 2-5) superalkali clusters.

    PubMed

    Srivastava, Ambrish Kumar; Misra, Neeraj

    2015-12-01

    Hyperlithiated clusters are known for their unusual bonding characteristics and lower ionization potentials. This study reports nonlinear optical (NLO) properties of a series of hyperlithiated clusters, Li n F (n = 2-5) for the first time. The structures of small Li n F (n = 2-5) clusters, obtained using second order Møller-Plesset perturbative method, are found to be stable against eliminations of F, F‾, and LiF. These Li n F species are stabilized by both ionic as well as covalent interactions. Our study shows that Li n F species can be thought of as superalkali-halogen (Li n  - F) clusters but belong to the class of superalkalies themselves. These clusters may also possess alkalide and/or electride characteristics due to excess electrons. The dipole moment, mean polarizability, and hyperpolarizability suggest their significant NLO responses which are explained using the highest occupied molecular orbital surfaces and TD-DFT analysis. The exceptionally large hyperpolarizability of Li2F (~10(5) a.u.) and its electride characteristics are particularly highlighted. This study may guide the researchers in the design of novel materials with significant NLO responses useful for electro-optical applications. Graphical Abstract Li2F superalkali resemble an electride in which the excess electron is pushed out by Li2 (+) moiety, leading to its high hyperpolarizability of order of 10(5) a.u. PMID:26546265

  7. Fracture characteristics of Ti-6Al-4V and Ti-5Al-2.5Fe with refined microstructure using hydrogen

    NASA Astrophysics Data System (ADS)

    Niinomi, M.; Gong, B.; Kobayashi, T.; Ohyabu, Y.; Toriyama, O.

    1995-05-01

    The hydrogenation behavior of Ti-6Al-4V, with the starting microstructures of coarse equiaxed α and coarse Widmanstätten α, respectively, was investigated under a hydrogen pressure of 0.1 MPa at temperatures between 843 and 1123 K. The hydrogen content was determined as a function of hydrogenation time, hydrogenation temperature, and hydrogen flow rate. The phases presented in the alloy of after hydrogenation were determined with X-ray and electron diffraction analysis in order to define the effect of Thermochemical Processing (TCP) on the microstructure of the alloy. Mechanical properties and fracture toughness of Ti-6Al-4V and Ti-5Al-2.5Fe subjected to the various TCP were then investigated. Hydrogenation of Ti-6Al-4V with the starting microstructure of coarse equiaxed α at 1023 K, just below hydrogen saturated β (denoted β″ (H)) transus temperature, produces a microstructure of a, orthohombic martensite (denoted α″ (H)) and β (H). Hydrogenation at 1123 K, above β (H) transus, results in a microstructure of α″ (H) and β (H). Microstructure refinement during TCP results mainly from decomposition of α″ (H) and ;β (H) into a fine mixture of α + β during dehydrogenation. An alternative TCP method is below β (H) transus hydrogenation (BTH), consisting of hydrogenation of the alloy below the hydrogenated β (H) transus temperature, air cooling to room temperature, and dehydrogenation at a lower temperature, which is found to improve mechanical properties significantly over a conventional TCP treatment. Compared with the untreated material, the BTH treatment increases the yield strength and increases the ultimate tensile strength significantly without decreasing the tensile elongation in the starting microstructure of coarse equiaxed α or with a little decrease in the tensile elongation in the starting microstructure of coarse Widmanstätten α, although the conventional TCP treatment results in a large decrease in elongation over the

  8. Estimating Causal Effects of Long-Term PM2.5 Exposure on Mortality in New Jersey

    PubMed Central

    Wang, Yan; Kloog, Itai; Coull, Brent A.; Kosheleva, Anna; Zanobetti, Antonella; Schwartz, Joel D.

    2016-01-01

    Background: Many studies have reported the associations between long-term exposure to PM2.5 and increased risk of death. However, to our knowledge, none has used a causal modeling approach or controlled for long-term temperature exposure, and few have used a general population sample. Objective: We estimated the causal effects of long-term PM2.5 exposure on mortality and tested the effect modifications by seasonal temperatures, census tract–level socioeconomic variables, and county-level health conditions. Methods: We applied a variant of the difference-in-differences approach, which serves to approximate random assignment of exposure across the population and hence estimate a causal effect. Specifically, we estimated the association between long-term exposure to PM2.5 and mortality while controlling for geographical differences using dummy variables for each census tract in New Jersey, a state-wide time trend using dummy variables for each year from 2004 to 2009, and mean summer and winter temperatures for each tract in each year. This approach assumed that no variable changing differentially over time across space other than seasonal temperatures confounded the association. Results: For each interquartile range (2 μg/m3) increase in annual PM2.5, there was a 3.0% [95% confidence interval (CI): 0.2, 5.9%] increase in all natural-cause mortality for the whole population, with similar results for people > 65 years old [3.5% (95% CI: 0.1, 6.9%)] and people ≤ 65 years old [3.1% (95% CI: –1.8, 8.2%)]. The mean summer temperature and the mean winter temperature in a census tract significantly modified the effects of long-term exposure to PM2.5 on mortality. We observed a higher percentage increase in mortality associated with PM2.5 in census tracts with more blacks, lower home value, or lower median income. Conclusions: Under the assumption of the difference-in-differences approach, we identified a causal effect of long-term PM2.5 exposure on mortality that was

  9. Integrating parasitology and marine ecology: Seven challenges towards greater synergy

    NASA Astrophysics Data System (ADS)

    Poulin, Robert; Blasco-Costa, Isabel; Randhawa, Haseeb S.

    2016-07-01

    Despite their very different historical origins as scientific disciplines, parasitology and marine ecology have already combined successfully to make important contributions to our understanding of the functioning of natural ecosystems. For example, robust assessments of the contribution of parasites to ecosystem biomass and energetics, and of their impact on community-wide biodiversity and food web structure, have all been made for the first time in marine systems. Nevertheless, for the marriage between parasitology and marine ecology to remain fruitful, several challenges must first be overcome. We discuss seven such challenges on the road to a greater synergy between these disciplines: (1) Raising awareness of parasitism as an ecological force by increasing the proportion of articles about parasites and diseases in marine ecology journals; (2) Making greater use of theory and conceptual frameworks from marine ecology to guide parasitological research; (3) Speeding up or at least maintaining the current rate at which marine parasites are found and described; (4) Elucidating a greater proportion of life cycles in all major groups of marine parasites; (5) Increasing the number of host-parasite model systems on which our knowledge is based; (6) Extending parasitological research offshore and into ocean depths; and (7) Developing, as needed, new epidemiological theory and transmission models for the marine environment. None of these challenges is insurmountable, and addressing just a few of them should guarantee that parasitology and marine ecology will continue to join forces and make further substantial contributions.

  10. Distribution of Permo-Carboniferous clastics of Greater Arabian basin

    SciTech Connect

    Al-Laboun, A.A.

    1987-05-01

    Strikingly correlative sequences of sediments composed of sandstones, siltstones, shales, and thin argillaceous carbonate beds are present, practically everywhere, underlying the Late Permian carbonates in the Greater Arabian basin. The Greater Arabian basin as defined here occupies the broad Arabian Shelf that borders the Arabian shield. This basin is composed of several smaller basins. These clastics are exposed as thin bands and scattered small exposures in several localities around the margins of the basin. The Permo-Carboniferous clastics are represented by the Unayzah Formation of Arabia, the Doubayat Group of Syria, the Hazro Formation of southeast Turkey, the Ga'arah Formation of Iraq, the Faraghan Formation of southwest Iran, and the Haushi Group of Oman. A Late Carboniferous-Early Permian age is assigned to these clastics because they contain fossil plants and palynomorphs. These sediments represent time-transgressive fluctuating sea deposits following a phase of regional emergence, erosion, and structural disturbance which preceded the Permian transgression. The basal contact of these clastics is marked by a well-pronounced angular unconformity with various older units, ranging in age from early Carboniferous to late Precambrian. This regional unconformity is probably related to the Hercynian movements. The upper contact is conformable with the Permian carbonates. The porous sandstones of the Permo-Carboniferous sediments are important hydrocarbon exploration targets. These reservoir rocks sometimes overlie mature source rocks and are capped by shales, marls, and tight carbonates. Significant quantities of hydrocarbons are contained in these reservoirs in different parts of the Greater Arabian basin.

  11. Assessing the geologic evolution of Greater Thaumasia, Mars

    NASA Astrophysics Data System (ADS)

    Hood, Don R.; Judice, Taylor; Karunatillake, Suniti; Rogers, Deanne; Dohm, James M.; Susko, David; Carnes, Lorraine K.

    2016-09-01

    The Greater Thaumasia region consists of three chemical provinces that include Syria, Solis, and Thaumasia Planae, the Corprates Rise, part of the Thaumasia Highlands, and the transition zone northwest of the Argyre basin. Chemical signatures obtained from the Mars Odyssey Gamma Ray Spectrometer suggest low abundances of K and Th to the west, with low H abundances and high Si abundances to the east, relative to the bulk Martian crust at midlatitudes. These observations are confirmed and quantified with a modified box and whisker analysis that simultaneously captures the degree of deviation and significance of the regionally anomalous chemistry. Motivated by regionally unique chemistry, as well as its diverse geological history, we characterize Greater Thaumasia in terms of chemistry, mineralogy, and mapped geology to determine how such complementary data record the evolution of this region. Our observations are inconsistent with a proposed salt-lubricated landslide origin, particularly given the lack of chemical or mineralogical signatures to support near-surface salt deposits that should arise over geological timescales. Our observations instead support magmatic processes, such as mantle evolution over geological time, which may impart the Si-enriched signature of the eastern portion of Greater Thaumasia as well as the K and Th depletion of the southeastern flank of Syria Planum. While the observed trend of decreasing K and Th from Noachian to Hesperian lavas is inconsistent with previous models of Martian mantle evolution, we see an increase in Ca content at the Noachian-Hesperian boundary, consistent with predictions from thermodynamic modeling.

  12. Estimating adult mortality attributable to PM2.5 exposure in China with assimilated PM2.5 concentrations based on a ground monitoring network.

    PubMed

    Liu, Jun; Han, Yiqun; Tang, Xiao; Zhu, Jiang; Zhu, Tong

    2016-10-15

    Estimates of mortality attributable to air pollution in China showed large differences among various studies, mainly arising from differences in exposure assessments and choice of the concentration-response function. The Chinese national monitoring network recently has included direct measurements of PM2.5 (particulates with aerodynamic diameter≤2.5μm), providing a potentially more reliable exposure assessment. We estimated adult premature mortalities due to PM2.5 across China in 2013 and mortality benefits for scenarios in which China meets the World Health Organization (WHO) Air Quality Guidelines (AQG) and three interim targets (ITs) for PM2.5. Attributable adult mortalities were estimated with assimilated spatial PM2.5 concentrations across China based on direct PM2.5 measurements from 506 PM2.5 monitoring sites and a regional air quality model, and using the integrated exposure-response model. Our results show that in China, 83% of the population lived in areas where PM2.5 concentrations exceeded the Chinese Ambient Air Quality Standard of 35μgm(-3). Premature mortalities attributed to PM2.5 nationwide were 1.37 million in total, and 0.69, 0.38, 0.13, and 0.17 million for stroke, ischemic heart disease, lung cancer, and chronic obstructive pulmonary disease, respectively. High population density areas exhibited the highest health risks attributed to air pollution. The mortality benefits will be 23%, 39%, 66%, and 83% of the total present premature mortalities (1.37 million mortalities) when PM2.5 concentrations in China meet the WHO IT-1, IT-2, IT-3, and AQG, respectively. Our study shows that integrating PM2.5 concentrations based on the national monitoring network with the regional air quality model provides an advanced exposure estimate method with potentials to further improve the accuracy for mortality estimate; much higher health benefits could be achieved if China adopted more stringent WHO guidelines for PM2.5. PMID:27266521

  13. Characterization of the chemical composition of PM2.5 emitted from on-road China III and China IV diesel trucks in Beijing, China.

    PubMed

    Wu, Bobo; Shen, Xianbao; Cao, Xinyue; Yao, Zhiliang; Wu, Yunong

    2016-05-01

    The composition of diesel exhaust fine particulate matter (PM2.5) is of growing interest because of its impacts on health and climatic factors and its application in source apportionment and aerosol modeling. We characterized the detailed chemical composition of the PM2.5, including the organic carbon (OC), elemental carbon (EC), water-soluble ions (WSIs), and elemental contents, emitted from China III and China IV diesel trucks (nine each) based on real-world measurements in Beijing using a portable emissions measurement system (PEMS). Carbonaceous compounds were the dominant components (totaling approximately 87%) of the PM2.5, similar to the results (greater than 80% of the PM2.5) of our previous study of on-road China III diesel trucks. In general, the amounts of individual component groups (carbonaceous compounds, WSIs, and elements) and PM2.5 emissions for China IV diesel trucks were lower than those of China III diesel trucks of the same size, except for the WSIs and elements for the light- and medium-duty diesel trucks. The EC/OC mass ratios were strongly dependent on the emission standards, and the ratios of China IV diesel trucks were higher than those of China III diesel trucks of the same size. The chemical species in the PM2.5 were significantly affected by the driving conditions. Overall, the emission factors (EFs) of the PM2.5 and OC under non-highway (NHW) driving conditions were higher than those under highway (HW) driving conditions, and the EC/OC mass ratios presented an increasing trend, with decreasing OC/PM2.5 and increasing EC/PM2.5 from NHW to HW driving conditions; similar trends were reported in our previous study. In addition, Pearson's correlation coefficients among the PM2.5 species were analyzed to determine the relationships among the various chemical components.

  14. Fine particulate matter components and emergency department visits among a privately insured population in Greater Houston.

    PubMed

    Liu, Suyang; Ganduglia, Cecilia M; Li, Xiao; Delclos, George L; Franzini, Luisa; Zhang, Kai

    2016-10-01

    Although adverse health effects of PM2.5 (particulate matter with aerodynamic diameter less than 2.5μm) mass have been extensively studied, it remains unclear regarding which PM2.5 components are most harmful. No studies have reported the associations between PM2.5 components and adverse health effects among a privately insured population. In our study, we estimated the short-term associations between exposure to PM2.5 components and emergency department (ED) visits for all-cause and cause-specific diseases in Greater Houston, Texas, during 2008-2013 using ED visit data extracted from a private insurance company (Blue Cross Blue Shield Texas [BCBSTX]). A total of 526,453 ED visits were included in our assessment, with an average of 236 (±63) visits per day. We selected 20 PM2.5 components from the U.S. Environmental Protection Agency's Chemical Speciation Network site located in Houston, and then applied Poisson regression models to assess the previously mentioned associations. Interquartile range increases in bromine (0.003μg/m(3)), potassium (0.048μg/m(3)), sodium ion (0.306μg/m(3)), and sulfate (1.648μg/m(3)) were statistically significantly associated with the increased risks in total ED of 0.71% (95% confidence interval (CI): 0.06, 1.37%), 0.71% (95% CI: 0.21, 1.22%), 1.28% (95% CI: 0.34, 2.24%), and 1.22% (95% CI: 0.23, 2.23%), respectively. Seasonal analysis suggested strongest associations occurred during the warm season. Our findings suggest that a privately insured population, presumably healthier than the general population, may be still at risk of adverse health effects due to exposure to ambient PM2.5 components. PMID:27235902

  15. Concentrations and chemical compositions of fine particles (PM2.5) during haze and non-haze days in Beijing

    NASA Astrophysics Data System (ADS)

    Zhang, Yang; Huang, Wei; Cai, Tianqi; Fang, Dongqing; Wang, Yuqin; Song, Jian; Hu, Min; Zhang, Yuanxun

    2016-06-01

    To investigate the chemical properties of PM2.5 and put forward reasonable control measures, daily samples of PM2.5 were collected at an urban site in Beijing from August 4 to September 3 of 2012 using two 2-channel samplers. Chemical analysis was conducted for eight water soluble inorganic ions (WSII, including Na+, NH4+, K+, Mg2 +, Ca2 +, Cl-, NO3-, and SO42 -), organic carbon (OC) and elementary carbon (EC). PM2.5 concentrations ranged from 8.8 to 218.6 μg m- 3, with an average concentration of 80.6 ± 57.3 μg m- 3. WSII, the most dominant PM2.5 constituents contributing 60 ± 18% of its mass, ranged from 3.1 to 172.2 μg m- 3. SO42 -, NO3-, and NH4+ dominated WSII (90 ± 28%) and their concentrations were 1.3-105.7 μg m- 3, 0.5-52.7 μg m- 3 and 0.3-33.5 μg m- 3, respectively. The concentrations of OC and EC were 3.0-28.8 μgC m- 3 and 0.8-7.4 μgC m- 3, constituting 17.6% and 4.9% of PM2.5, respectively. Three serious pollution episodes (haze days) occurred during the campaign. PM2.5 and its chemical species showed substantial increases during haze episodes. The greater enhancement factors for SO42 - (4.5), NO3- (4.0), and NH4+ (4.2) during haze days compared to non-haze days were obtained, suggesting that these secondary inorganic ions play important roles in the formation of haze. The average ratio of NO3-/SO42 - was 0.52. Ion balance calculations showed that PM2.5 samples were acidic during haze periods and close to neutral during non-haze days. Correlation analysis between the major ions was conducted and the results suggested that the main forms of NH4+ might be (NH4)2SO4. In addition, the variations between haze days and non-haze days for OC, EC, and the ratio of OC/EC were discussed.

  16. [Effects of biodiesel on fine particles (PM2.5) and polycyclic aromatic hydrocarbons from diesel engine].

    PubMed

    Tan, Ji-hua; Shi, Xiao-yan; Zhang, Jie; He, Ke-bin; Ma, Yong-liang; Ge, Yun-shan; Tan, Jian-wei

    2009-10-15

    PM2.5 emissions and polycyclic aromatic hydrocarbons (PAHs) in PM2.5 of pure biodiesel derived from different feedstocks were investigated and compared with diesel fuel. B100-1 (soyabean oil derived), B100-2 (waste oil derived) and diesel fuel were tested on a diesel engine bench at four operating conditions, including two steady speeds of different loads. The fine particles were collected by fiber quartz filter and particle phase PAHs were analyzed by GC-MS. Compared with diesel fuel, biodiesel decreased PM2.5 emission rates with a maximal reduction rate of 37.3% at operating modes of high loads, while increased PM2.5 emission rates at low loads. PAHs emission rates from biodiesel decreased at all tested modes, with a maximal reduction rate of 77.6%. The emission rates of PM2.5 and PAHs of B100-2 were 14.7% and 17.8% times of B100-1. Low molecular weight PAHs dominated in the emission of three fuels with phenanthrene as maxima and 2-ring and 3-ring PAHs accounted for more than 50% of the total PAHs. Toxic equivalence of PAHs emissions of biodiesel was decreased greatly compared with that of diesel.

  17. Particulate matter (PM2.5) and carbon monoxide from secondhand smoke outside bars and restaurants in downtown Athens, Georgia.

    PubMed

    St Helen, Gideon; Hall, Daniel B; Kudon, Louis H; Pearce, John; Baptiste, Shanece; Ferguson, Sylvia; Green, Tiffany; Naeher, Luke P

    2011-10-01

    In the study described in this article, the authors' objective was to measure particles < or = 2.5 microm in aerodynamic diameter (PM2.5) and carbon monoxide (CO) in outdoor waiting areas and patios of restaurants and bars in downtown Athens, Georgia, where indoor smoking is banned. The authors also wanted to investigate whether the measured concentrations are directly associated with the number of cigarettes lit in these settings. Real-time PM2.5 and CO were monitored on four summer weekend afternoons/evenings in outdoor waiting areas or patios at five locations in Athens. In addition, smokers and pedestrians present or passing and motorized vehicles passing each sampling location were counted. PM2.5 levels were significantly higher than levels at the control location (all p-values > .001). Carbon monoxide levels outside the restaurant and bar sites did not differ significantly from the control. The results of the authors' study indicate that (1) secondhand smoke (SHS) leads to significant increases in PM2.5 outside of restaurants and bars; and (2) although CO can be used as a proxy for SHS in these outdoor environments, its levels remain relatively low.

  18. Chemical composition of PM2.5 particles in Salamanca, Guanajuato Mexico: Source apportionment with receptor models

    NASA Astrophysics Data System (ADS)

    Herrera Murillo, Jorge; Campos Ramos, Arturo; Ángeles García, Felipe; Blanco Jiménez, Salvador; Cárdenas, Beatriz; Mizohata, Akira

    2012-04-01

    The National Institute of Ecology, through Management General for Environmental Research and Training (DGCENICA) carried out a sampling campaign where a total of 21 elements were determined in 140 PM2.5 samples from one sampling site located in the city of Salamanca, Guanajuato-Mexico between November 2006 and November 2007. The annual average PM2.5 concentration was 45 μg/m3 almost three times the Mexican Annual standard for PM2.5. Mineral, organic and elemental carbon were the most important components present in particles PM2.5. Two advanced receptor models, UNMIX and positive matrix factorization (PMF) were used for PM2.5 source identification. Four and six sources were identified by UNMIX and PMF, respectively, from a combined dataset including 15 chemical species. Source categories were determined based on both, component abundances in the source profiles, and their temporal characteristics. Overall, different sources were identified as the major contributors: heavy fuels combustion, traditional brick production-agricultural burning, crustal, road traffic and secondary organic aerosols.

  19. Black Carbon and Particulate Matter (PM2.5) Concentrations in New York City’s Subway Stations

    PubMed Central

    2015-01-01

    The New York City (NYC) subway is the main mode of transport for over 5 million passengers on an average weekday. Therefore, airborne pollutants in the subway stations could have a significant impact on commuters and subway workers. This study looked at black carbon (BC) and particulate matter (PM2.5) concentrations in selected subway stations in Manhattan. BC and PM2.5 levels were measured in real time using a Micro-Aethalometer and a PDR-1500 DataRAM, respectively. Simultaneous samples were also collected on quartz filters for organic and elemental carbon (OC/EC) analysis and on Teflon filters for gravimetric and trace element analysis. In the underground subway stations, mean real time BC concentrations ranged from 5 to 23 μg/m3, with 1 min average peaks >100 μg/m3, while real time PM2.5 levels ranged from 35 to 200 μg/m3. Mean EC levels ranged from 9 to 12.5 μg/m3. At street level on the same days, the mean BC and PM2.5 concentrations were below 3 and 10 μg/m3, respectively. This study shows that both BC soot and PM levels in NYC’s subways are considerably higher than ambient urban street levels and that further monitoring and investigation of BC and PM subway exposures are warranted. PMID:25409007

  20. [Pollution characteristics of carbonaceous aerosols in PM2.5 during typical winter days in Wuxi City ].

    PubMed

    Yun, Long-long; Lu, Fan; Zhang, Tian-shu; Wu, De-xia; Sheng, Shi-jie; Lu, Yi-huai; Liu, Jian-guo

    2014-09-01

    The purpose of this study was to investigate the process of haze in winter and the variation of carbonaceous aerosols in haze days. Continuous measurements of PM2.5 and meteorological parameters were conducted from Dec 3rd ,2013 to Jan 3rd, 2014, in Wuxi City. The carbonaceous component was quantified with the thermal/optical transmission (TOT) method. The results showed that: Three times of haze progresses occurred during the sampling period. Cold air, wind and rainfall were the most efficient ways to improve air quality. The mass concentration of PM2.5, OC and EC were (132.38 ± 87.17) μg.m-3, (22.80±9.77) μg.m-3 and (2.08 ± 1. 63) μg.m-3, respectively. The TC accounted for 23.57% of the PM2.5; at the same time, the TC and PM2.5 were found to be strongly correlated (correlation coefficients = 0. 730). There was a negative correlation between the ratio of carbonaceous aerosol in PM2.5 and the concentration of PM2.5, and the ratio in haze days was lower than that in normal days, which suggested that secondary inorganic particles (SO(2-)(4) , NO(-)(3), NH: ) may have a fast growth in haze days. Average OC/EC ratio was 12. 83, and there was a poor correlation between OC and EC, indicating that secondary pollutants might exist. The secondary organic carbon (SOC) was estimated to be 9.04 μg.m -3, accounting for 40. 96% of OC.

  1. Ethyl-2, 5-dihydroxybenzoate displays dual activity by promoting osteoblast differentiation and inhibiting osteoclast differentiation.

    PubMed

    Kwon, Byeong-Ju; Lee, Mi Hee; Koo, Min-Ah; Kim, Min Sung; Seon, Gyeung Mi; Han, Jae-Jin; Park, Jong-Chul

    2016-03-11

    The interplay between bone-forming osteoblasts and bone-resorbing osteoclasts is essential for balanced bone remodeling. In this study, we evaluate the ability of ethyl-2, 5-dihyrdoxybenzoate (E-2, 5-DHB) to affect both osteoblast and osteoclast differentiation for bone regeneration. Osteogenic differentiation of human mesenchymal stem cells (hMSCs) was quantified by measuring alkaline phosphatase (ALP) activity and calcium deposition. To evaluate osteoclast differentiation, we investigated the effect of E-2, 5-DHB on RANKL-activated osteoclastogenesis in RAW 264.7 cells. E-2, 5-DHB enhanced ALP activity and inhibited RAW 264.7 cell osteoclastogenesis in vitro. To assess the in vivo activity of E-2, 5-DHB, hMSCs were delivered subcutaneosuly alone or in combination with E-2, 5-DHB in an alginate gel into the backs of nude-mice. Histological and immunohistochemical evaluation showed significantly higher calcium deposition in the E-2, 5-DHB group. Osteocalcin (OCN) was highly expressed in cells implanted in the gels containing E-2, 5-DHB. Our results suggest that E-2, 5-DHB can effectively enhance osteoblast differentiation and inhibit osteoclast differentiation both in vitro and in vivo. Understanding the dual function of E-2, 5-DHB on osteoblast and osteoclast differentiation will aid in future development of E-2, 5-DHB as a material for bone tissue engineering.

  2. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for...

  3. 40 CFR Table C-4 to Subpart C of... - Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Specifications for PM 10, PM 2.5 and PM 10-2.5 Candidate Equivalent Methods C Table C-4 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-4 Table C-4 to Subpart C of Part 53—Test Specifications for...

  4. Weekly cycle of magnetic characteristics of the daily PM2.5 and PM2.5-10 in Beijing, China

    NASA Astrophysics Data System (ADS)

    Shi, Meinan; Wu, Huaichun; Zhang, Shihong; Li, Haiyan; Yang, Tianshui; Liu, Wei; Liu, He

    2014-12-01

    In recent years, Beijing has been shown to suffer one of the most serious air pollution problems of any major world city. The concentrations of particulate matter (PM) pollutants, PM2.5-10 and PM2.5, are commonly used as air pollution indexes. We conducted a detailed environmental magnetism study to investigate possible sources of air pollution in Beijing, China, using 283 pairs of the PM2.5 and PM2.5-10 samples collected daily from July 2010 to June 2011. Rock magnetic measurements, including magnetic susceptibility, anhysteretic remanent magnetization, isothermal remanent magnetization, saturation isothermal remanent magnetization, hysteresis loops, first-order reversal curves (FORCs), and thermomagnetism, indicate that the main magnetic mineral is low-coercivity pseudo-single domain (PSD) magnetite. Scanning electron microscope (SEM) observations and energy dispersive X-ray spectroscopy (EDS) analyses on the PM indicate that the major magnetic phase is coarse-grained magnetite, which is most likely from automobile exhausts and braking system debris. Magnetic parameters of PM2.5 and PM2.5-10 show significant seasonal patterns that may be attributed to domestic heating enhancing magnetization of the PM during late autumn to early spring. Power spectral analyses and box-whisker plots indicate that the magnetic parameters have strong weekly variations that may be due to traffic emissions. These results indicate that magnetic parameters can be used as efficient proxies for monitoring Beijing's air pollution, and that the atmospheric environment may be improved by controlling vehicle emissions.

  5. Fine (PM2.5), coarse (PM2.5-10), and metallic elements of suspended particulates for incense burning at Tzu Yun Yen temple in central Taiwan.

    PubMed

    Fang, Guor-Cheng; Chang, Cheng-Nan; Chu, Chia-Chium; Wu, Yuh-Shen; Pi-Cheng Fu, Peter; Chang, Shyh-Chyi; Yang, I-Lin

    2003-06-01

    Ambient suspended particulate concentrations were measured at Tzu Yun Yen temple (120 degrees, 34('), 10(") E; 24 degrees, 16('), 12(") N) in this study. This is representative of incense burning and semi-open sampling sites. The Universal-sampler collected fine and coarse particle material was used to measure suspended particulate concentrations, and sampling periods were from 16/08/2001 to 2/1/2002 at Tzu Yun Yen temple. In addition, metallic element concentrations, compositions of PM(2.5) and PM(2.5-10) for incense burning at Tzu Yun Yen temple were also analyzed in this study. The PM(2.5)/PM(10) ratios ranged between 31% and 87% and averaged 70+/-11% during incense the burning period, respectively. The median metallic element concentration order for these elements is Fe>Zn>Cr>Cd>Pb>Mn>Ni>Cu in fine particles (PM(2.5)) at the Tzu Yun Yen temple sampling site. The median metallic element concentration order for these elements is Fe>Zn>Cr>Pb>Cd>Ni>Mn>Cu in coarse particle (PM(2.5-10)) at the Tzu Yun Yen temple sampling site. Fine particulates (PM(2.5)) are the main portion of PM(10) at Tzu Yun Yen temple in this study. From the point of view of PM(10), these data reflect that the elements Fe, Zn, and Cr were the major elements distributed at Tzu Yun Yen temple in this study.

  6. Accumulation of 2',5'-oligoadenylates in encephalomyocarditis virus-infected mice.

    PubMed Central

    Hearl, W G; Johnston, M I

    1987-01-01

    Levels of 2',5'-oligoadenylates (2-5A) in various tissues of murine encephalomyocarditis virus (EMCV)-infected mice were determined and compared with those found in pathogen-free mice and in mice treated with the interferon inducer poly(I).poly(C). In control, pathogen-free mice, liver, spleen, brain, and kidney tissues possessed levels of 2-5A below 1 pmol/g of tissue, demonstrating that 2-5A was not a major component of uninfected mouse tissue. All control tissues had low basal levels (0.3 to 2.0 pmol/h per g) of 2-5A synthetase, the enzyme responsible for 2-5A production. After mice were injected intravenously with the interferon inducer poly(I).poly(C), circulating interferon, 2-5A synthetase, and 2-5A were elevated with increasing doses of double-stranded RNA. The greatest response to poly(I).poly(C) occurred in the kidney, in which enzyme levels increased 5-fold and 2-5A levels increased 24-fold to 15 pmol/g. Mice that were infected with EMCV also possessed elevated levels of 2-5A and 2-5A synthetase in the four tissues examined, although the relative distribution differed from that observed with poly(I).poly(C), indicating that the interferon inducer affects the concentration and location of intracellular 2-5A. Brain, spleen, and kidney tissues from EMCV-infected mice contained seven- to eightfold more 2-5A than control tissues did. The nanomolar levels of 2-5A in the tissues of EMCV-infected mice provide evidence that 2-5A may play a role in the antiviral response in an intact animal. In both poly(I).poly(C)- and EMCV-treated mice, the levels of 2-5A recovered from the tissues were not directly proportional to the amount of 2-5A synthetase present. These results indicate that factors other than the level of 2-5A synthetase controlled the accumulation of 2-5A in tissues. PMID:2437319

  7. Inhibition of light emission in a 2.5D photonic structure

    SciTech Connect

    Peretti, Romain; Seassal, Christian; Viktorovich, Pierre; Letartre, Xavier

    2014-07-14

    We analyse inhibition of emission in a 2.5D photonic structures made up of a photonic crystal (PhC) and Bragg mirrors using Finite Differences Time Domaine (FDTD) simulations. A comparison is made between an isolated PhC membrane and the same PhC suspended onto a Bragg mirror or sandwiched between 2 Bragg mirrors. Strong inhibition of the Purcell factor is observed in a broad spectral range, whatever the in-plane orientation and location of the emitting dipole. We analysed these results numerically and theoretically by simulating the experimentally observed lifetime of a collection of randomly distributed emitters, showing that their average emission rate is decreased by more than one decade, both for coupled or isolated emitters.

  8. Construction and testing of the 2.5m mass driver

    NASA Technical Reports Server (NTRS)

    Snow, W. R.; Oneill, G. K.

    1979-01-01

    Presented are the designs used in the construction of the 2.5 m mass driver and the results of the initial testing program. The mass driver consists of equal length sections of acceleration and deceleration each containing 59 drive coils of 13.1 cm caliber. Intermediate energy storage is provided by sector capacitors which are recharged every half cycle by an external power source. The drive coils are individually energized through SCR's with timing supplied by position sensing optical detectors. The drive consists of two phases which operate in quadrature. The initial bucket to be propelled through the mass driver contains two coils of aluminum wire chilled to liquid nitrogen temperatures to momentarily sustain superconducting field intensities. Magnetic flight is generated by eddy current repulsion from six copper guide strips lining the mass driver. Nominal acceleration is 5000 m/sec per sec giving a maximum bucket velocity of 112 m/s.

  9. Decreasing trends of suspended particulate matter and PM2.5 concentrations in Tokyo, 1990-2010.

    PubMed

    Hara, Kunio; Homma, Junichi; Tamura, Kenji; Inoue, Mariko; Karita, Kanae; Yano, Eiji

    2013-06-01

    In Tokyo, the annual average suspended particulate matter (SPM) and PM2.5 concentrations have decreased in the past two decades. The present study quantitatively evaluated these decreasing trends using data from air-pollution monitoring stations. Annual SPM and PM2.5 levels at 83 monitoring stations and hourly SPM and PM2.5 levels at four monitoring stations in Tokyo, operated by the Tokyo Metropolitan Government, were used for analysis, together with levels of co-pollutants and meteorological conditions. Traffic volume in Tokyo was calculated from the total traveling distance of vehicles as reported by the Ministry of Land, Infrastructure, Transport, and Tourism. High positive correlations between SPM levels and nitrogen oxide levels, sulfur dioxide levels, and traffic volume were determined. The annual average SPM concentration declined by 62.6%from 59.4 microg/m3 in 1994 to 22.2 microg/m3 in 2010, and PM2.5 concentration also declined by 49.8% from 29.3 microg/m3 in 2001 to 14.7 microg/m3 in 2010. Likewise, the frequencies of hourly average SPM and PM2.5 concentrations exceeding the daily guideline values have significantly decreased since 2001 and the hourly average SPM or PM2.5 concentrations per traffic volume for each time period have also significantly decreased since 2001. However SPM and PM2.5 concentrations increased at some monitoring stations between 2004 and 2006 and from 2009 despite strengthened environmental regulations and improvements in vehicle engine performance. The annual average SPM and PM2.5 concentrations were positively correlated with traffic volumes and in particular with the volume of diesel trucks. These results suggest that the decreasing levels of SPM and PM2.5 in Tokyo may be attributable to decreased traffic volumes, along with the effects of stricter governmental regulation and improvements to vehicle engine performance, including the fitting of devices for exhaust emission reduction. PMID:23858999

  10. Decreasing trends of suspended particulate matter and PM2.5 concentrations in Tokyo, 1990-2010.

    PubMed

    Hara, Kunio; Homma, Junichi; Tamura, Kenji; Inoue, Mariko; Karita, Kanae; Yano, Eiji

    2013-06-01

    In Tokyo, the annual average suspended particulate matter (SPM) and PM2.5 concentrations have decreased in the past two decades. The present study quantitatively evaluated these decreasing trends using data from air-pollution monitoring stations. Annual SPM and PM2.5 levels at 83 monitoring stations and hourly SPM and PM2.5 levels at four monitoring stations in Tokyo, operated by the Tokyo Metropolitan Government, were used for analysis, together with levels of co-pollutants and meteorological conditions. Traffic volume in Tokyo was calculated from the total traveling distance of vehicles as reported by the Ministry of Land, Infrastructure, Transport, and Tourism. High positive correlations between SPM levels and nitrogen oxide levels, sulfur dioxide levels, and traffic volume were determined. The annual average SPM concentration declined by 62.6%from 59.4 microg/m3 in 1994 to 22.2 microg/m3 in 2010, and PM2.5 concentration also declined by 49.8% from 29.3 microg/m3 in 2001 to 14.7 microg/m3 in 2010. Likewise, the frequencies of hourly average SPM and PM2.5 concentrations exceeding the daily guideline values have significantly decreased since 2001 and the hourly average SPM or PM2.5 concentrations per traffic volume for each time period have also significantly decreased since 2001. However SPM and PM2.5 concentrations increased at some monitoring stations between 2004 and 2006 and from 2009 despite strengthened environmental regulations and improvements in vehicle engine performance. The annual average SPM and PM2.5 concentrations were positively correlated with traffic volumes and in particular with the volume of diesel trucks. These results suggest that the decreasing levels of SPM and PM2.5 in Tokyo may be attributable to decreased traffic volumes, along with the effects of stricter governmental regulation and improvements to vehicle engine performance, including the fitting of devices for exhaust emission reduction.

  11. Analysis of PM10, PM2.5, and PM2 5-10 concentrations in Santiago, Chile, from 1989 to 2001.

    PubMed

    Koutrakis, Petros; Sax, Sonja N; Sarnat, Jeremy A; Coull, Brent; Demokritou, Phil; Oyola, Pedro; Garcia, Javier; Gramsch, Ernesto

    2005-03-01

    Daily particle samples were collected in Santiago, Chile, at four urban locations from January 1, 1989, through December 31, 2001. Both fine PM with da < 2.5 microm (PM2.5) and coarse PM with 2.5 < da < 10 microm (PM2.5-10) were collected using dichotomous samplers. The inhalable particle fraction, PM10, was determined as the sum of fine and coarse concentrations. Wind speed, temperature and relative humidity (RH) were also measured continuously. Average concentrations of PM2.5 for the 1989-2001 period ranged from 38.5 microg/m3 to 53 microg/m3. For PM2.5-10 levels ranged from 35.8-48.2 microg/m3 and for PM10 results were 74.4-101.2 microg/m3 across the four sites. Both annual and daily PM2.5 and PM10 concentration levels exceeded the U.S. National Ambient Air Quality Standards and the European Union concentration limits. Mean PM2.5 levels during the cold season (April through September) were more than twice as high as those observed in the warm season (October through March); whereas coarse particle levels were similar in both seasons. PM concentration trends were investigated using regression models, controlling for site, weekday, month, wind speed, temperature, and RH. Results showed that PM2.5 concentrations decreased substantially, 52% over the 12-year period (1989-2000), whereas PM2.5-10 concentrations increased by approximately 50% in the first 5 years and then decreased by a similar percentage over the following 7 years. These decreases were evident even after controlling for significant climatic effects. These results suggest that the pollution reduction programs developed and implemented by the Comisión Nacional del Medio Ambiente (CONAMA) have been effective in reducing particle levels in the Santiago Metropolitan region. However, particle levels remain high and it is thus imperative that efforts to improve air quality continue.

  12. Selective cytotoxicity of PAMAM G5 core–PAMAM G2.5 shell tecto-dendrimers on melanoma cells

    PubMed Central

    Schilrreff, Priscila; Mundiña-Weilenmann, Cecilia; Romero, Eder Lilia; Morilla, Maria Jose

    2012-01-01

    Background The controlled introduction of covalent linkages between dendrimer building blocks leads to polymers of higher architectural order known as tecto-dendrimers. Because of the few simple steps involved in their synthesis, tecto-dendrimers could expand the portfolio of structures beyond commercial dendrimers, due to the absence of synthetic drawbacks (large number of reaction steps, excessive monomer loading, and lengthy chromatographic separations) and structural constraints of high-generation dendrimers (reduction of good monodispersity and ideal dendritic construction due to de Gennes dense-packing phenomenon). However, the biomedical uses of tecto-dendrimers remain unexplored. In this work, after synthesizing saturated shell core–shell tecto-dendrimers using amine-terminated polyamidoamine (PAMAM) generation 5 (G5) as core and carboxyl-terminated PAMAM G2.5 as shell (G5G2.5 tecto-dendrimers), we surveyed for the first time the main features of their interaction with epithelial cells. Methods Structural characterization of G5G2.5 was performed by polyacrylamide gel electrophoresis, matrix-assisted laser desorption time-of-flight mass spectrometry, and microscopic techniques; their hydrodynamic size and Z-potential was also determined. Cellular uptake by human epidermal keratinocytes, colon adenocarcinoma, and epidermal melanoma (SK-Mel-28) cells was determined by flow cytometry. Cytotoxicity was determined by mitochondrial activity, lactate dehydrogenase release, glutathione depletion, and apoptosis/necrosis measurement. Results The resultant 60%–67% saturated shell, 87,000-dalton G5G2.5 (mean molecular weight) interacted with cells in a significantly different fashion in comparison to their building blocks and to its closest counterpart, PAMAM G6.5. After being actively taken up by epithelial cells, G5G2.5 caused cytotoxicity only on SK-Mel-28 cells, including depletion of intracellular glutathione and fast necrosis that was manifested above 5 μM G5

  13. Source sector and region contributions to BC and PM2.5 in Central Asia

    DOE PAGES

    Kulkarni, S.; Sobhani, N.; Miller-Schulze, J. P.; Shafer, M. M.; Schauer, J. J.; Solomon, P. A.; Saide, P. E.; Spak, S. N.; Cheng, Y. F.; Denier van der Gon, H. A. C.; et al

    2015-02-18

    pollutants. Aerosols at these sites are shown to reflect dust, biomass burning, and anthropogenic sources from Europe; South, East, and Central Asia; and Russia depending on the time period. Simulations for a reference 2030 emission scenario based on pollution abatement measures already committed to in current legislation show that PM2.5 and BC concentrations in the region increase, with BC growing more than PM2.5 on a relative basis. This suggests that both the health impacts and the climate warming associated with these particles may increase over the next decades unless additional control measures are taken. The importance of observations in CA to help characterize the changes that are rapidly taking place in the region are discussed.« less

  14. Suicide in married couples in Sweden: Is the risk greater in same-sex couples?

    PubMed

    Björkenstam, Charlotte; Andersson, Gunnar; Dalman, Christina; Cochran, Susan; Kosidou, Kyriaki

    2016-07-01

    Minority sexual orientation is a predictor of suicide ideation and attempts, though its association with suicide mortality is less clear. We capitalize on Sweden's extensively linked databases, to investigate whether, among married individuals, same-sex marriage is associated with suicide. Using a population-based register design, we analyzed suicide risk among same-sex married women and men (n = 6456), as compared to different-sex married women and men (n = 1181723) in Sweden. We selected all newly partnered or married individuals in the intervening time between 1/1/1996 and 12/31/2009 and followed them with regard to suicide until 12/31/2011. Multivariate Poisson regression was used to calculate adjusted incidence risk ratios (IRR) with 95 % confidence intervals (CI). The risk of suicide was higher among same-sex married individuals as compared to different-sex married individuals (IRR 2.7, 95 % CI 1.5-4.8), after adjustment for time at risk and socioeconomic confounding. Sex-stratified analyses showed a tentatively elevated risk for same-sex married women (IRR 2.5, 95 % CI 0.8-7.7) as compared to different-sex married women. Among same-sex married men the suicide risk was nearly three-fold greater as compared to different-sex married (IRR 2.895 % CI 1.5-5.5). This holds true also after adjustment for HIV status. Even in a country with a comparatively tolerant climate regarding homosexuality such as Sweden, same-sex married individuals evidence a higher risk for suicide than other married individuals. PMID:27168192

  15. Suicide in married couples in Sweden: Is the risk greater in same-sex couples?

    PubMed

    Björkenstam, Charlotte; Andersson, Gunnar; Dalman, Christina; Cochran, Susan; Kosidou, Kyriaki

    2016-07-01

    Minority sexual orientation is a predictor of suicide ideation and attempts, though its association with suicide mortality is less clear. We capitalize on Sweden's extensively linked databases, to investigate whether, among married individuals, same-sex marriage is associated with suicide. Using a population-based register design, we analyzed suicide risk among same-sex married women and men (n = 6456), as compared to different-sex married women and men (n = 1181723) in Sweden. We selected all newly partnered or married individuals in the intervening time between 1/1/1996 and 12/31/2009 and followed them with regard to suicide until 12/31/2011. Multivariate Poisson regression was used to calculate adjusted incidence risk ratios (IRR) with 95 % confidence intervals (CI). The risk of suicide was higher among same-sex married individuals as compared to different-sex married individuals (IRR 2.7, 95 % CI 1.5-4.8), after adjustment for time at risk and socioeconomic confounding. Sex-stratified analyses showed a tentatively elevated risk for same-sex married women (IRR 2.5, 95 % CI 0.8-7.7) as compared to different-sex married women. Among same-sex married men the suicide risk was nearly three-fold greater as compared to different-sex married (IRR 2.895 % CI 1.5-5.5). This holds true also after adjustment for HIV status. Even in a country with a comparatively tolerant climate regarding homosexuality such as Sweden, same-sex married individuals evidence a higher risk for suicide than other married individuals.

  16. Influence of meteorological conditions on PM 2.5 and PM 2.5-10 concentrations during the monsoon season in Hanoi, Vietnam

    NASA Astrophysics Data System (ADS)

    Hien, P. D.; Bac, V. T.; Tham, H. C.; Nhan, D. D.; Vinh, L. D.

    Twenty-four hour samples of air particulate matter with aerodynamic diameters from 2 to 10 μm (PM 10) and <2.5 μm (PM 2.5) were collected in Hanoi throughout 1 year since August 1998. The air sampler was located in a meteorological garden where routine surface observations and upper air radiosoundings were conducted. Very high PM 2.5 and PM 2.5-10 concentrations were observed in conjunction with the occurrence of nocturnal radiation inversions from October to December and subsidence temperature inversions (STI) from January to March. In the first case, the PM 2.5-10 fraction was much enhanced and particulate pollution was significantly higher at night than in daytime. During the occurence of STIs particulate mass was almost evenly distributed among the two fractions and no significant diurnal variations in concentrations were observed. In summer (May-September) particulate pollution was much lower than in winter. The multiple regression of 24-h particulate concentrations against meteorological parameters for both the winter and summer monsoon periods shows that the most important determinants of PM 2.5 are wind speed and air temperature, while rainfall and relative humidity largely control the daily variations of PM 2.5-10, indicating the high abundance of soil dust in this fraction. As to turbulence parameters, among the determinants of 24-h particulate concentrations are the vertical gradients of potential temperature and wind speed recorded at 06.30 and 18.30, respectively. Meteorological parameters could explain from 60% to 74% of the day-to-day variations of particulate concentrations.

  17. Particulate matter 2.5 (PM2.5) personal exposure evaluation on mechanics and administrative officers at the motor vehicle testing center at Pulo Gadung, DKI Jakarta.

    PubMed

    Rizky, Zuly Prima; Yolla, Patricia Bebby; Ramdhan, Doni Hikmat

    2016-03-01

    Exposure to fine particulate matter (PM2.5) in both the short and long term has been known to cause deaths and health effects, especially related to the heart, blood vessels, and lungs. Based on this information, researchers conducted this study at a motor vehicle testing center unit at Pulo Gadung, in Jarkarta, to determine the concentration of PM2.5 that workers were exposed to. The major source of PM2.5 in this area is from the exhaust of gas emissions from motor vehicles, which is one of the largest contributors to the levels of PM in urban areas. Ten mechanics were picked from 16 mechanics that work in this station. Four administration workers from different posts were also picked to participate. The researcher conducted the PM2.5 personal exposure measurement during weekdays from 6 to 14 April 2015 (2 workers/day). This research was conducted to measure the particle number concentration with size <2.5 μm. The average personal exposure concentrations of PM2.5 in the study period received by the group of mechanics amounted to 149.01 μm/m3 while the administrative officer group that consisted of four administrative workers were exposed to an average of 103.28 μm/m3. Once converted and compared with the World Health Organization Air Quality Guidelines, the PM2.5 exposure of the mechanics and administrative officers exceeded the recommended exposure (25 μm/m3).

  18. Fine particles (PM2.5) in ambient air of Lucknow city due to fireworks on Diwali festival.

    PubMed

    Barman, S C; Singh, Ramesh; Negi, M P S; Bhargava, S K

    2009-09-01

    People burn crackers world over on different occasions in different countries to express their happiness. Fireworks in large amounts aggravate the level of air pollutants and cause significant short-term air quality degradation with possible impact on human health. Fine particles (PM2.5 < or = 2.5 microm), which may pose detrimental effects on human health and ecosystems were monitored in a residential area of Lucknow city to assess the elevated level due to bursting of firecrackers during Diwali festival. The 24 hr mean PM2.5 of normal day, pre Diwali day, Diwali day and post Diwali day was found to be 124, 154, 352 and 174 microg m(-3) respectively and much above the US-EPA limit (65 microg m(-3)). The 12 hr mean concentration of PM2.5 on Diwali night (591 microg m(-3)) increased 3.9 fold than the respective night of normal day (159 microg m(-3)) and was significantly higher (p<0.01) than normal day and pre and post Diwali night. Mean comparison showed that Diwali day was significantly (p<0.01) different from others (except post Diwali day) and for this high accumulation during night time, after fireworks (suspension) was found to be more responsible than the period of lighting of crackers (formation). This study indicated that there is high accumulation of PM2.5 generated due to fireworks on Diwali festival which remains suspended in the air for up to 20 hr During this period, extra mass burden of 289 microg m(-3) equivalent to 1.9 normal day (of this study) was imposed in the environment. The short-term high accumulation of PM2.5 is a matter of serious concern for city dwellers as it can penetrate deep into the lungs and cause many respiratory and cardiovascular diseases.

  19. Assessing the accuracy of ANFIS, EEMD-GRNN, PCR, and MLR models in predicting PM2.5

    NASA Astrophysics Data System (ADS)

    Ausati, Shadi; Amanollahi, Jamil

    2016-10-01

    Since Sanandaj is considered one of polluted cities of Iran, prediction of any type of pollution especially prediction of suspended particles of PM2.5, which are the cause of many diseases, could contribute to health of society by timely announcements and prior to increase of PM2.5. In order to predict PM2.5 concentration in the Sanandaj air the hybrid models consisting of an ensemble empirical mode decomposition and general regression neural network (EEMD-GRNN), Adaptive Neuro-Fuzzy Inference System (ANFIS), principal component regression (PCR), and linear model such as multiple liner regression (MLR) model were used. In these models the data of suspended particles of PM2.5 were the dependent variable and the data related to air quality including PM2.5, PM10, SO2, NO2, CO, O3 and meteorological data including average minimum temperature (Min T), average maximum temperature (Max T), average atmospheric pressure (AP), daily total precipitation (TP), daily relative humidity level of the air (RH) and daily wind speed (WS) for the year 2014 in Sanandaj were the independent variables. Among the used models, EEMD-GRNN model with values of R2 = 0.90, root mean square error (RMSE) = 4.9218 and mean absolute error (MAE) = 3.4644 in the training phase and with values of R2 = 0.79, RMSE = 5.0324 and MAE = 3.2565 in the testing phase, exhibited the best function in predicting this phenomenon. It can be concluded that hybrid models have accurate results to predict PM2.5 concentration compared with linear model.

  20. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    DOE PAGES

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; et al

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperaturemore » over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.« less

  1. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane

    SciTech Connect

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M.; Savee, John D.; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A.; Osborn, David L.; Violi, Angela; Taatjes, Craig A.

    2014-09-19

    The product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). The interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Furthermore, quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  2. Photoionization mass spectrometric measurements of initial reaction pathways in low-temperature oxidation of 2,5-dimethylhexane.

    PubMed

    Rotavera, Brandon; Zádor, Judit; Welz, Oliver; Sheps, Leonid; Scheer, Adam M; Savee, John D; Akbar Ali, Mohamad; Lee, Taek Soon; Simmons, Blake A; Osborn, David L; Violi, Angela; Taatjes, Craig A

    2014-11-01

    Product formation from R + O2 reactions relevant to low-temperature autoignition chemistry was studied for 2,5-dimethylhexane, a symmetrically branched octane isomer, at 550 and 650 K using Cl-atom initiated oxidation and multiplexed photoionization mass spectrometry (MPIMS). Interpretation of time- and photon-energy-resolved mass spectra led to three specific results important to characterizing the initial oxidation steps: (1) quantified isomer-resolved branching ratios for HO2 + alkene channels; (2) 2,2,5,5-tetramethyltetrahydrofuran is formed in substantial yield from addition of O2 to tertiary 2,5-dimethylhex-2-yl followed by isomerization of the resulting ROO adduct to tertiary hydroperoxyalkyl (QOOH) and exhibits a positive dependence on temperature over the range covered leading to a higher flux relative to aggregate cyclic ether yield. The higher relative flux is explained by a 1,5-hydrogen atom shift reaction that converts the initial primary alkyl radical (2,5-dimethylhex-1-yl) to the tertiary alkyl radical 2,5-dimethylhex-2-yl, providing an additional source of tertiary alkyl radicals. Quantum-chemical and master-equation calculations of the unimolecular decomposition of the primary alkyl radical reveal that isomerization to the tertiary alkyl radical is the most favorable pathway, and is favored over O2-addition at 650 K under the conditions herein. The isomerization pathway to tertiary alkyl radicals therefore contributes an additional mechanism to 2,2,5,5-tetramethyltetrahydrofuran formation; (3) carbonyl species (acetone, propanal, and methylpropanal) consistent with β-scission of QOOH radicals were formed in significant yield, indicating unimolecular QOOH decomposition into carbonyl + alkene + OH.

  3. An integrated PM2.5 source apportionment study: Positive Matrix Factorisation vs. the chemical transport model CAMx

    NASA Astrophysics Data System (ADS)

    Bove, M. C.; Brotto, P.; Cassola, F.; Cuccia, E.; Massabò, D.; Mazzino, A.; Piazzalunga, A.; Prati, P.

    2014-09-01

    Receptor and Chemical Transport Models are commonly used tools in source apportionment studies, even if different expertise is required. We describe an experiment using both approaches to apportion the PM2.5 (i.e., particulate matter with aerodynamic diameters below 2.5 μm) sources in the city of Genoa (Italy). A sampling campaign was carried out to collect PM2.5 samples daily for approximately six month during 2011 in three sites. The subsequent compositional analyses included the speciation of elements, major ions and both organic and elemental carbon; these data produced a large database for receptor modelling through Positive Matrix Factorisation (PMF). In the same period, a meteorological and air quality modelling system was implemented based on the mesoscale numerical weather prediction model WRF and the chemical transport model CAMx to obtain meteorological and pollutant concentrations up to a resolution of 1.1 km. The source apportionment was evaluated by CAMx over the same period that was used for the monitoring campaign using the Particulate Source Apportionment Technology tool. Even if the source categorisations were changed (i.e., groups of time-correlated compounds in PMF vs. activity categories in CAMx), the PM2.5 source apportionment by PMF and CAMx produced comparable results. The different information provided by the two approaches (e.g., real-world factor profile by PMF and apportionment of a secondary aerosol by CAMx) was used jointly to elucidate the composition and origin of PM2.5 and to develop a more general methodology. When studying the primary and secondary components of PM, the main anthropogenic sources in the area were road transportation, energy production/industry and maritime emissions, accounting for 40%-50%, 20%-30% and 10%-15%, of PM2.5, respectively.

  4. Chemical composition and sources of PM2.5 and TSP collected at Qinghai Lake during summertime

    NASA Astrophysics Data System (ADS)

    Zhang, Ningning; Cao, Junji; Liu, Suixin; Zhao, ZhuZi; Xu, Hongmei; Xiao, Shun

    2014-03-01

    PM2.5 and total suspended particulate (TSP) samples were collected from June to September 2010 at Qinghai Lake, northeastern Tibetan Plateau. The concentrations of major water-soluble ions, 10 elements, elemental carbons (ECs) and organic carbons (OCs) were quantified. Mass concentrations of PM2.5 and TSP were 21.27 ± 10.70 μg m- 3 and 41.47 ± 20.25 μg m- 3, respectively, and the mean ratio of PM2.5/TSP was 0.51. The greatest anion and cation in both PM2.5 and TSP samples were SO42 - and Ca2 +, respectively. Crustal elements, such as Ca, Fe and K, were the main elements in our aerosol samples, and their enrichment factors (EFs) were lower than 10. EFs for Pb, As, and Zn were greater than 10, indicating that they were influenced by anthropogenic sources. EC concentrations were 0.33 ± 0.17 μg m- 3 and 0.47 ± 0.28 μg m- 3, whereas OC concentrations were 1.49 ± 0.63 μg m- 3 and 2.30 ± 0.95 μg m- 3 in PM2.5 and TSP, respectively. Based on the calculated ratios of EC/TC and K+/EC, most of the ECs were found to be related to biomass burning emissions. Because of the pollution from local sources, the ratios of OC/EC were 4.77 ± 1.32 and 5.23 ± 1.39 in PM2.5 and TSP, respectively, which were lower than those of other remote sites. Salt particles produced by the salty lake reacted with acid gases and caused most of the nitrates and a small fraction of sulfate to be distributed in coarse mode; Cl deficit was also observed in our aerosol samples. Results of backward trajectories and correlation analysis show that the concentrations of SO4 2-, OCs, As, Pb, and Zn, were influenced by the long-distance transport from eastern China.

  5. Organic compounds of PM2.5 in Mexico Valley: spatial and temporal patterns, behavior and sources.

    PubMed

    Amador-Muñoz, O; Villalobos-Pietrini, R; Miranda, J; Vera-Avila, L E

    2011-03-15

    A longitudinal study on spatial and temporal behavior of particles less than 2.5 μm (PM(2.5)), solvent extracted organic matter (SEOM), polycyclic aromatic hydrocarbons (PAH), n-alkanes and nitro-PAH was carried out for a full year in 2006, at five sites simultaneously around the Metropolitan Zone of Mexico Valley (MZMV). There is rather uniform distribution of PM(2.5) and SEOM in the MZMV regarding gravimetric mass concentration, while some specific organic chemical components showed mass heterogeneity. The highest mass concentrations of target compounds occurred in the dry seasons with respect to the rainy season. Bonfires and fireworks are probably responsible for extreme values of PM(2.5), SEOM and PAH (≥ 228 gmol(-1)). Benzo[ghi]perylene was the most abundant PAH, with C(24)-C(26) the most abundant n-alkanes and 2-nitrofluoranthene and 9-nitroanthracene the most abundant nitro-PAH. The northeast zone was the area with the greatest presence of sources of incomplete diesel combustion, while the central for gasoline combustion. In the southwest, the biogenic sources were more abundant over the anthropogenic sources. This was opposite to the other sites. Factor analysis allowed us to relate different compounds to emitting sources. Three main factors were associated with combustion, pyrolysis and biogenic primary sources while the other factors were associated with secondary organic aerosol formation and industry. Correlation analyses indicated that SEOM originates from different primary emission sources or is formed by different processes than the other variables, except in southwest. Associations among variables suggest that PM(2.5) in the northwest and in the southeast originated mainly from primary emissions or consisted of primary organic compounds. PM(2.5) in the northeast, central and southwest contains a greater proportion of secondary organic compounds, with the less oxidized organic aerosols in the northeast and the most aged organic aerosol in the

  6. Airborne concentrations of PM(2.5) and diesel exhaust particles on Harlem sidewalks: a community-based pilot study.

    PubMed Central

    Kinney, P L; Aggarwal, M; Northridge, M E; Janssen, N A; Shepard, P

    2000-01-01

    Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:10706526

  7. p59OASL, a 2'-5' oligoadenylate synthetase like protein: a novel human gene related to the 2'-5' oligoadenylate synthetase family.

    PubMed Central

    Hartmann, R; Olsen, H S; Widder, S; Jorgensen, R; Justesen, J

    1998-01-01

    The 2'-5' oligoadenylate synthetases form a well conserved family of interferon induced proteins, presumably present throughout the mammalian class. Using the Expressed Sequence Tag databases, we have identified a novel member of this family. This protein, which we named p59 2'-5' oligoadenylate synthetase-like protein (p59OASL), shares a highly conserved N-terminal domain with the known forms of 2'-5' oligoadenylate synthetases, but differs completely in its C-terminal part. The C-terminus of p59OASL is formed of two domains of ubiquitin-like sequences. Here we present the characterisation of a full-length cDNA clone, the genomic sequence and the expression pattern of this gene. We have addressed the evolution of the 2'-5' oligoadenylate synthetase gene family, in the light of both this new member and new 2'-5' oligoadenylate synthetase sequence data from other species, which have recently appeared in the databases. PMID:9722630

  8. Using Machine Learning to Estimate Global PM2.5 for Environmental Health Studies

    PubMed Central

    Lary, D. J.; Lary, T.; Sattler, B.

    2015-01-01

    With the increasing awareness of health impacts of particulate matter, there is a growing need to comprehend the spatial and temporal variations of the global abundance of ground-level airborne particulate matter (PM2.5). Here we use a suite of remote sensing and meteorological data products together with ground based observations of PM2.5 from 8,329 measurement sites in 55 countries taken between 1997 and 2014 to train a machine learning algorithm to estimate the daily distributions of PM2.5 from 1997 to the present. We demonstrate that the new PM2.5 data product can reliably represent global observations of PM2.5 for epidemiological studies. An analysis of Baltimore schizophrenia emergency room admissions is presented in terms of the levels of ambient pollution. PM2.5 appears to have an impact on some aspects of mental health. PMID:26005352

  9. [Characteristics of organic carbon and elemental carbon in PM2.5 in Shuozhou City].

    PubMed

    Liu, Feng-xian; Peng, Lin; Bai, Hui-ling; Mu, Ling; Liu, Xiao-feng; Li, Li-juan; Liu, Xin

    2015-03-01

    PM2.5 samples were collected at four sampling sites in Shuozhou during the heating and non-heating periods. Organic carbon (OC) and elemental carbon (EC) in PM2.5 were analyzed by Elementar Analysensysteme GmbH vario EL cube and the concentration, spatial and temporal distribution characteristics and main sources of OC and EC were studied. The results were as following: average concentrations of OC and EC in PM2.5 during non-heating period were (14.3 ± 2.7) μg x m(-3) and (10.3 ± 3.1) μg x m(-3) while (23.3 ± 5.9) μg xm(-3) and (20.0 ± 5.7) μg x m(-3) during heating period. The concentrations of OC and EC at four sites during the heating period were higher than those during the non-heating period. The concentrations of OC and EC at SW site during heating were the highest which were 28.5 μg x m(-3) and 28.1 μg x m(-3) while the concentrations at PS sites during non-heating period were the highest, which were 17.7 μg x m(-3) and 14.1 μg x m(-3). The ratios between OC and EC during the heating and non-heating period were all below 2 and the correlation between OC and EC was not good with R2 of 0. 66 during heating period and 0.52 during non-heating period which indicated that sources of carbon aerosols were complex. Carbonaceous aerosol pollution should be reduced by controlling the primary emissions such as coal combustion, vehicle exhaust and biomass burning, and by paying attention to secondary pollution at the same time to improve the air quality in Shuozhou City. The concentrations of SOC during heating and non-heating period were (6.44 ± 2.77) μg x m(-3) and (4.11 ± 1.92) μg x m(-3). PMID:25929042

  10. PM 2.5 and PM 10: The influence of sugarcane burning on potential cancer risk

    NASA Astrophysics Data System (ADS)

    Silva, Flavio S.; Cristale, Joyce; André, Paulo A.; Saldiva, Paulo H. N.; Marchi, Mary R. R.

    2010-12-01

    In Brazil, sugarcane fields are often burned to facilitate manual harvesting, and this burning causes environmental pollution from the large amounts of soot released into the atmosphere. This material contains numerous organic compounds such as PAHs. In this study, the concentrations of PAHs in two particulate-matter fractions (PM 2.5 and PM 10) in the city of Araraquara (SE Brazil, with around 200,000 inhabitants and surrounded by sugarcane plantations) were determined during the sugarcane harvest (HV) and non-harvest (NHV) seasons in 2008 and 2009. The sampling strategy included four campaigns, with 60 samples in the NHV season and 220 samples in the HV season. The PM 2.5 and PM 10 fractions were collected using a dichotomous sampler (10 L min -1, 24 h) with Teflon™ filters. The filter sets were extracted (ultrasonic bath with hexane/acetone (1:1 v/v)) and analyzed by HPLC/Fluorescence. The median concentration for total PAHs (PM 2.5 in 2009) was 0.99 ng m -3 (NHV) and 3.3 ng m -3 (HV). In the HV season, the total concentration of carcinogenic PAHs (benz(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene) was 5 times higher than in the NHV season. B(a)P median concentrations were 0.017 ng m -3 and 0.12 ng m -3 for the NHV and HV seasons, respectively. The potential cancer risk associated with exposure through inhalation of these compounds was estimated based on the benzo[a]pyrene toxic equivalence (BaP eq), where the overall toxicity of a PAH mixture is defined by the concentration of each compound multiplied by its relative toxic equivalence factor (TEF). BaP eq median (2008 and 2009 years) ranged between 0.65 and 1.0 ng m -3 and 1.2-1.4 ng m -3 for the NHV and HV seasons, respectively. Considering that the maximum permissible BaP eq in ambient air is 1 ng m -3, related to the increased carcinogenic risk, our data suggest that the level of human exposure to PAHs in cities surrounded by sugarcane crops where the burning process is used

  11. Associations of PM2.5 and black carbon concentrations with traffic, idling, background pollution, and meteorology during school dismissals.

    PubMed

    Richmond-Bryant, J; Saganich, C; Bukiewicz, L; Kalin, R

    2009-05-01

    An air quality study was performed outside a cluster of schools in the East Harlem neighborhood of New York City. PM(2.5) and black carbon concentrations were monitored using real-time equipment with a one-minute averaging interval. Monitoring was performed at 1:45-3:30 PM during school days over the period October 31-November 17, 2006. The designated time period was chosen to capture vehicle emissions during end-of-day dismissals from the schools. During the monitoring period, minute-by-minute volume counts of idling and passing school buses, diesel trucks, and automobiles were obtained. These data were transcribed into time series of number of diesel vehicles idling, number of gasoline automobiles idling, number of diesel vehicles passing, and number of automobiles passing along the block adjacent to the school cluster. Multivariate regression models of the log-transform of PM(2.5) and black carbon (BC) concentrations in the East Harlem street canyon were developed using the observation data and data from the New York State Department of Environmental Conservation on meteorology and background PM(2.5). Analysis of variance was used to test the contribution of each covariate to variability in the log-transformed concentrations as a means to judge the relative contribution of each covariate. The models demonstrated that variability in background PM(2.5) contributes 80.9% of the variability in log[PM(2.5)] and 81.5% of the variability in log[BC]. Local traffic sources were demonstrated to contribute 5.8% of the variability in log[BC] and only 0.43% of the variability in log[PM(2.5)]. Diesel idling and passing were both significant contributors to variability in log[BC], while diesel passing was a significant contributor to log[PM(2.5)]. Automobile idling and passing did not contribute significant levels of variability to either concentration. The remainder of variability in each model was explained by temperature, along-canyon wind, and cross-canyon wind, which were

  12. Sexual predators, energy development, and conservation in greater Yellowstone.

    PubMed

    Berger, Joel; Beckmann, Jon P

    2010-06-01

    In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies-recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)-differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in-migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.

  13. Residential indoor PM 10 and PM 2.5 in Hong Kong and the elemental composition

    NASA Astrophysics Data System (ADS)

    Chao, Christopher Y.; Wong, Kelvin K.

    Indoor air particulate samples were collected in 34 homes and their adjacent outdoor environments in Hong Kong during the fall and winter seasons. It was found that the mean indoor PM 2.5 and PM 10 concentrations were 45.0 and 63.3 μg m -3, respectively. The corresponding mean outdoor levels were 47.0 and 69.5 μg m -3, respectively. The indoor particulate levels were found to be about 2-4 times higher than those in the homes in western countries where most are located in suburb areas with a much better ambient air quality. Pearson paired t-tests were conducted on the data and it was found that poor correlation was seen in the indoor and the outdoor particulate concentrations. This was probably due to the fact that windows were closed more often in the fall and winter seasons keeping the ventilation rate low, plus the factor that window type air conditioners were used commonly in Hong Kong, which again, constituted to a low air change rate. Both the indoor and the outdoor elemental compositions of the particulate samples collected in these 34 homes were identified by proton-induced X-ray emission analysis. Seventeen elements were identified. The mean inorganic elemental compositions in the indoor PM 2.5 and PM 10 samples were 6.4 and 10.2 μg m -3, respectively while those in the outdoor samples were 7.9 and 14.1 μg m -3, respectively. Enrichment factor analysis was performed and it was noted that those species existing in fine mode were highly enriched (bromine, lead, nickel, potassium, sulfur, vanadium and zinc) while those species existing in the coarse mode had their enrichment factors close to 1 (aluminum, calcium, iron, magnesium, silicon, sodium and titanium).

  14. Spatial Variation of the Relationship between PM 2.5 Concentrations and Meteorological Parameters in China.

    PubMed

    Lin, Gang; Fu, Jingying; Jiang, Dong; Wang, Jianhua; Wang, Qiao; Dong, Donglin

    2015-01-01

    Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5 concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5 dataset, this paper explores the relationship between PM2.5 concentrations and meteorological parameters and their spatial variance in China for the period 2001-2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5 had a strong and stable correlation with meteorological parameters. In particular, PM2.5 had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5 and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5 and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010. PMID:26295046

  15. Metal composition of ambient PM2.5 influences severity of allergic airways disease in mice.

    PubMed Central

    Gavett, Stephen H; Haykal-Coates, Najwa; Copeland, Lisa B; Heinrich, Joachim; Gilmour, M Ian

    2003-01-01

    Children living in Hettstedt in eastern Germany have been reported to have a higher prevalence of sensitization to common aeroallergens than another cohort living in the neighboring city of Zerbst; these differences correlated with the presence of industrial air pollution. Samples of fine particulate matter (< 2.5 micro m aerodynamic diameter; PM(2.5)) collected in Hettstedt in 1999 had several-fold higher levels of zinc, magnesium, lead, copper, and cadmium than samples from Zerbst. To determine if the results from epidemiologic studies could be repeated in an animal model, we administered PM(2.5) from Hettstedt and Zerbst to ovalbumin-allergic mice. In Balb/c mice, PM(2.5) from Hettstedt, but not PM(2.5) from Zerbst or control filter extract, caused a significant increase in immediate responses to ovalbumin challenge when aspirated 2 hr before challenge, but not when aspirated immediately before sensitization 2 weeks earlier. Antigen-specific IgE was increased by Hettstedt PM(2.5) whether administered before sensitization or challenge. Airway responsiveness to methacholine aerosol and lung inflammatory cell numbers were significantly increased only in allergic mice exposed to Hettstedt PM(2.5) before challenge. Both Hettstedt and Zerbst PM(2.5) significantly increased lung injury parameters and proinflammatory cytokines. These results are consistent with epidemiologic findings and show that metal composition of ambient PM(2.5) influences the severity of allergic respiratory disease. PMID:12948886

  16. PM2.5 constituents and hospital emergency-room visits in Shanghai, China.

    PubMed

    Qiao, Liping; Cai, Jing; Wang, Hongli; Wang, Weibing; Zhou, Min; Lou, Shengrong; Chen, Renjie; Dai, Haixia; Chen, Changhong; Kan, Haidong

    2014-09-01

    Although ambient PM2.5 has been linked to adverse health effects, the chemical constituents that cause harm are largely unclear. Few prior studies in a developing country have reported the health impacts of PM2.5 constituents. In this study, we examined the short-term association between PM2.5 constituents and emergency room visits in Shanghai, China. We measured daily concentrations of PM2.5, organic carbon (OC), elemental carbon (EC), and eight water-soluble ions between January 1, 2011 and December 31, 2012. We analyzed the data using overdispersed generalized linear Poisson models. During our study period, the mean daily average concentration of PM2.5 in Shanghai was 55 μg/m(3). Major contributors to PM2.5 mass included OC, EC, sulfate, nitrate, and ammonium. For a 1-day lag, an interquartile range increment in PM2.5 mass (36.47 μg/m(3)) corresponded to 0.57% [95% confidence interval (CI): 0.13%, 1.01%] increase of emergency room visits. In all the three models used, we found significant positive associations of emergency room visits with OC and EC. Our findings suggest that PM2.5 constituents from the combustion of fossil fuel (e.g., OC and EC) may have an appreciable influence on the health impact attributable to PM2.5.

  17. Regulation of alternative polyadenylation by Nkx2-5 and Xrn2 during mouse heart development.

    PubMed

    Nimura, Keisuke; Yamamoto, Masamichi; Takeichi, Makiko; Saga, Kotaro; Takaoka, Katsuyoshi; Kawamura, Norihiko; Nitta, Hirohisa; Nagano, Hiromichi; Ishino, Saki; Tanaka, Tatsuya; Schwartz, Robert J; Aburatani, Hiroyuki; Kaneda, Yasufumi

    2016-01-01

    Transcription factors organize gene expression profiles by regulating promoter activity. However, the role of transcription factors after transcription initiation is poorly understood. Here, we show that the homeoprotein Nkx2-5 and the 5'-3' exonuclease Xrn2 are involved in the regulation of alternative polyadenylation (APA) during mouse heart development. Nkx2-5 occupied not only the transcription start sites (TSSs) but also the downstream regions of genes, serving to connect these regions in primary embryonic cardiomyocytes (eCMs). Nkx2-5 deficiency affected Xrn2 binding to target loci and resulted in increases in RNA polymerase II (RNAPII) occupancy and in the expression of mRNAs with long 3'untranslated regions (3' UTRs) from genes related to heart development. siRNA-mediated suppression of Nkx2-5 and Xrn2 led to heart looping anomaly. Moreover, Nkx2-5 genetically interacts with Xrn2 because Nkx2-5(+/-)Xrn2(+/-), but neither Nkx2-5(+/-)nor Xrn2(+/-), newborns exhibited a defect in ventricular septum formation, suggesting that the association between Nkx2-5 and Xrn2 is essential for heart development. Our results indicate that Nkx2-5 regulates not only the initiation but also the usage of poly(A) sites during heart development. Our findings suggest that tissue-specific transcription factors is involved in the regulation of APA. PMID:27331609

  18. Spatial Variation of the Relationship between PM2.5 Concentrations and Meteorological Parameters in China

    PubMed Central

    Lin, Gang; Fu, Jingying; Jiang, Dong; Wang, Jianhua; Wang, Qiao; Dong, Donglin

    2015-01-01

    Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5 concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5 dataset, this paper explores the relationship between PM2.5 concentrations and meteorological parameters and their spatial variance in China for the period 2001–2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5 had a strong and stable correlation with meteorological parameters. In particular, PM2.5 had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5 and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5 and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010. PMID:26295046

  19. Spatial Variation of the Relationship between PM 2.5 Concentrations and Meteorological Parameters in China.

    PubMed

    Lin, Gang; Fu, Jingying; Jiang, Dong; Wang, Jianhua; Wang, Qiao; Dong, Donglin

    2015-01-01

    Epidemiological studies around the world have reported that fine particulate matter (PM2.5) is closely associated with human health. The distribution of PM2.5 concentrations is influenced by multiple geographic and socioeconomic factors. Using a remote-sensing-derived PM2.5 dataset, this paper explores the relationship between PM2.5 concentrations and meteorological parameters and their spatial variance in China for the period 2001-2010. The spatial variations of the relationships between the annual average PM2.5, the annual average precipitation (AAP), and the annual average temperature (AAT) were evaluated using the Geographically Weighted Regression (GWR) model. The results indicated that PM2.5 had a strong and stable correlation with meteorological parameters. In particular, PM2.5 had a negative correlation with precipitation and a positive correlation with temperature. In addition, the relationship between the variables changed over space, and the strong negative correlation between PM2.5 and the AAP mainly appeared in the warm temperate semihumid region and northern subtropical humid region in 2001 and 2010, with some localized differences. The strong positive correlation between the PM2.5 and the AAT mainly occurred in the mid-temperate semiarid region, the humid, semihumid, and semiarid warm temperate regions, and the northern subtropical humid region in 2001 and 2010.

  20. Chemistry and biochemistry of 2',5'-oligoadenylate-based antisense strategy.

    PubMed

    Adah, S A; Bayly, S F; Cramer, H; Silverman, R H; Torrence, P F

    2001-08-01

    This review describes the application of a natural defense mechanism to develop effective agents for the post-transcriptional control of gene expression. 2-5A is a unique 2',5'-phosphodiester bond linked oligoadenylate, (pp)p5'A2'(p5'A)(n), that is elaborated in virus-infected interferon-treated cells. The 2-5A system is an RNA degradation pathway that is an important mechanistic component of interferon's action against certain viruses. It may also play a role in the anticellular effects of interferon and in general RNA decay. A major player in the 2-5A-system is the latent and constitutive 2-5A-dependent ribonuclease (RNase L) which upon activation by 2-5A, degrades RNA. This RNase L enzyme can be recruited for antisense therapeutics by linking it to an appropriate oligonucleotide targeted to a chosen RNA. Syntheses of 2-5A, its analogues, 2-5A-antisense, and its modifications are detailed herein. Applications of 2-5A-antisense to particular targets such as HIV, PKR, chronic myelogenous leukemia, telomerase, and respiratory syncytical virus are described. PMID:11472236

  1. SAMPLING, ANALYSIS, AND PROPERTIES OF PRIMARY PM-2.5: APPLICATION TO COAL-FIRED UTILITY BOILERS

    SciTech Connect

    Allen L. Robinson; Spyros N. Pandis; Eric Lipsky; Charles Stainer; Natalie Anderson; Satoshi Takahama; Sarah Rees

    2003-02-01

    A dilution sampler was used to examine the effects of dilution ratio and residence time on the particulate emissions from a pilot-scale pulverized coal combustor. Measurements include the particle size distribution from 0.003 to 2.5 {micro}m, PM{sub 2.5} mass emission rate and PM2.5 composition (OC/EC, major ions, and elemental). Hot filter samples were also collected simultaneously in order to compare the dilution sampler measurement with standard stack sampling methodologies such as EPA Method 5. Measurements were made both before and after the bag-house, the particle control device used on the coal combustor. Measurements were made with three different coal types and a coal-biomass blend. The residence time and dilution ratio do not influence the PM{sub 2.5} mass emission rate, but have a significant effect on the size distribution and total number emissions. Measurements made before the bag-house showed increasing the residence time dramatically decreases the total particle number concentration, and shifts the particle mass to larger sizes. The effects of residence time can be explained quantitatively by the coagulation of the emitted particles. Measurements made after the bag-house were not affected by coagulation due to the lower concentration of particles. Nucleation of sulfuric acid vapor within the dilution was an important source of ultrafine particles. This nucleation is strongly a function of dilution ratio because of the competition between condensation and nucleation. At low dilution ratios condensation dominates and little nucleation is observed; increasing the dilution ratio promotes nucleation because of the corresponding decrease in available surface area per unit volume for condensation. No nucleation was observed after the bag house where conditions greatly favor nucleation over condensation; we suspect that the bag house removed the SO{sub 3} in the flue gas. Exhaust SO{sub 3} levels were not measured during these experiments. Dilution caused

  2. Characteristics of concentrations and water-soluble inorganic ions in PM2.5 in Handan City, Hebei province, China

    NASA Astrophysics Data System (ADS)

    Meng, C. C.; Wang, L. T.; Zhang, F. F.; Wei, Z.; Ma, S. M.; Ma, X.; Yang, J.

    2016-05-01

    In order to explore the spatial, temporal, and chemical characteristics of fine particulate matter (PM2.5) pollution in Handan city, China, a comprehensive dataset including continuous online observations at four air quality monitoring stations in 2013 and 2014, and the concentrations of water-soluble inorganic ions (WSII) (NO3-, SO42 -, NH4+, Cl-, Na+, Mg2 +, K+, Ca2 +) in PM2.5 samples collected in four representative seasons in 2013 and 2014 are analyzed in this study. And the principal component analysis (PCA) method is applied to identify the source of WSII in Handan. Our results indicate that PM2.5 concentration decreased from 139.4 μg/m3 in 2013 to 116.0 μg/m3 in 2014 on annual average. Spatial variations of PM2.5 mass are not pronounced, indicating that PM2.5 is nearly evenly spread over the study area. The seasonal variations of PM2.5 concentration are significant, normally with 1.7 to 2.4 times higher in winter than in summer. The concentrations of TWSII (total water-soluble inorganic ions) remain relatively stable in two years, with annual averages of 63.1 μg/m3 in 2013 and 57.2 μg/m3 in 2014. SNA (SO42 -, NO3-, NH4+) dominates in the TWSII, accounting for ~ 87% of the TWSII. Similar to PM2.5, WSII exhibits obvious seasonal variations with higher concentrations in autumn and winter, lower in spring and summer. PM2.5 samples are acidic in spring, summer and autumn of 2013, while in winter of 2013 and all seasons of 2014, they are alkaline. SO42 -, NO3- are formed mainly through homogeneous reactions, heterogeneous reactions also exist in winter. Finally, the major sources of WSII in Handan are identified as the mixture of secondary origin, coal combustion, biomass burning (46.1%), dust sources (25.8%), and motor vehicle (12.3%).

  3. Potential application of VIIRS Day/Night Band for monitoring nighttime surface PM2.5 air quality from space

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Aegerter, Clint; Xu, Xiaoguang; Szykman, James J.

    2016-01-01

    A pilot study is conducted to illustrate the potential of using radiance data collected by the Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite for particulate matter (PM) air quality monitoring at night. The study focuses on the moonless and cloudless nights in Atlanta, Georgia during August-October 2012. We show with radiative transfer calculations that DNB at night is sensitive to the change of aerosols and much less sensitive to the change of water vapor in the atmosphere illuminated by common outdoor light bulbs at the surface. We further show both qualitatively that the contrast of DNB images can indicate the change of air quality at the urban scale, and quantitatively that change of light intensity during the night (as characterized by VIIRS DNB) reflects the change of surface PM2.5. Compared to four meteorological variables (u and v components of surface wind speed, surface pressure, and columnar water vapor amount) that can be obtained from surface measurements, the DNB light intensity is the only variable that shows either the largest or second largest correlation with surface PM2.5 measured at 5 different sites. A simple multivariate regression model with consideration of the change of DNB light intensity can yield improved estimate of surface PM2.5 as compared to the model with consideration of meteorological variables only. Cross validation of this DNB-based regression model shows that the estimated surface PM2.5 concentration has nearly no bias and a linear correlation coefficient (R) of 0.67 with respect to the corresponding hourly observed surface PM2.5 concentration. Furthermore, ground-based observations support that surface PM2.5 concentration at the VIIRS night overpass (˜1:00 am local) time is representative of daily-mean PM2.5 air quality (R = 0.82 and mean bias of -0.1 μg m-3). While the potential appears promising, mapping surface PM2.5 from

  4. Ambient temperature enhanced acute cardiovascular-respiratory mortality effects of PM2.5 in Beijing, China

    NASA Astrophysics Data System (ADS)

    Li, Yi; Ma, Zhiqiang; Zheng, Canjun; Shang, Yu

    2015-12-01

    Studies have shown that temperature could modify the effect of ambient fine particles on mortality risk. In assessing air pollution effects, temperature is usually considered as a confounder. However, ambient temperature can alter people's physiological response to air pollution and might "modify" the impact of air pollution on health outcomes. This study investigated the interaction between daily PM2.5 and daily mean temperature in Beijing, China, using data for the period 2005-2009. Bivariate PM2.5-temperature response surfaces and temperature-stratified generalized additive model (GAM) were applied to study the effect of PM2.5 on cardiovascular, respiratory mortality, and total non-accidental mortality across different temperature levels. We found that low temperature could significantly enhance the effect of PM2.5 on cardiovascular mortality. For an increase of 10 μg/m3 in PM2.5 concentration in the lowest temperature range (-9.7˜2.6 °C), the relative risk (RR) of cardiovascular mortality increased 1.27 % (95 % CI 0.38˜2.17 %), which was higher than that of the whole temperature range (0.59 %, 95 % CI 0.22-1.16 %). The largest effect of PM2.5 on respiratory mortality appeared in the high temperature range. For an increase of 10 μg/m3 in PM2.5 concentration, RR of respiratory mortality increased 1.70 % (95 % CI 0.92˜3.33 %) in the highest level (23.50˜31.80 °C). For the total non-accidental mortality, significant associations appeared only in low temperature levels (-9.7˜2.6 °C): for an increase of 10 μg/m3 in current day PM2.5 concentration, RR increased 1.27 % (95 % CI 0.46˜2.00 %) in the lowest temperature level. No lag effect was observed. The results suggest that in air pollution mortality time series studies, the possibility of an interaction between air pollution and temperature should be considered.

  5. Ambient temperature enhanced acute cardiovascular-respiratory mortality effects of PM2.5 in Beijing, China.

    PubMed

    Li, Yi; Ma, Zhiqiang; Zheng, Canjun; Shang, Yu

    2015-12-01

    Studies have shown that temperature could modify the effect of ambient fine particles on mortality risk. In assessing air pollution effects, temperature is usually considered as a confounder. However, ambient temperature can alter people's physiological response to air pollution and might "modify" the impact of air pollution on health outcomes. This study investigated the interaction between daily PM2.5 and daily mean temperature in Beijing, China, using data for the period 2005-2009. Bivariate PM2.5-temperature response surfaces and temperature-stratified generalized additive model (GAM) were applied to study the effect of PM2.5 on cardiovascular, respiratory mortality, and total non-accidental mortality across different temperature levels. We found that low temperature could significantly enhance the effect of PM2.5 on cardiovascular mortality. For an increase of 10 μg/m(3) in PM2.5 concentration in the lowest temperature range (-9.7∼2.6 °C), the relative risk (RR) of cardiovascular mortality increased 1.27 % (95 % CI 0.38∼2.17 %), which was higher than that of the whole temperature range (0.59 %, 95 % CI 0.22-1.16 %). The largest effect of PM2.5 on respiratory mortality appeared in the high temperature range. For an increase of 10 μg/m(3) in PM2.5 concentration, RR of respiratory mortality increased 1.70 % (95 % CI 0.92∼3.33 %) in the highest level (23.50∼31.80 °C). For the total non-accidental mortality, significant associations appeared only in low temperature levels (-9.7∼2.6 °C): for an increase of 10 μg/m(3) in current day PM2.5 concentration, RR increased 1.27 % (95 % CI 0.46∼2.00 %) in the lowest temperature level. No lag effect was observed. The results suggest that in air pollution mortality time series studies, the possibility of an interaction between air pollution and temperature should be considered.

  6. Fracture characteristics, microstructure, and tissue reaction of Ti-5Al-2.5Fe for orthopedic surgery

    NASA Astrophysics Data System (ADS)

    Niinomi, Mitsuo; Kobayashi, Toshiro; Toriyama, Osamu; Kawakami, Noriaki; Ishida, Yoshihito; Matsuyama, Yukihiro

    1996-12-01

    The microstructure of Ti-5Al-2.5Fe, which is expected to be used widely as an implant material not only for artificial hip joints but also for instrumentations of scoliosis surgery, was variously changed by heat treatments. The effect of the microstructure on mechanical properties, fracture toughness, and rotating-bending fatigue strength in the air and simulated body environment, that is, Ringer’s solution, was then investigated. Furthermore, the effect of the living body environment on mechanical properties and fracture toughness in Ti-5Al-2.5Fe were investigated on the specimens implanted into rabbit for about 11 months. The data of Ti-5Al-2.5Fe were compared with those of Ti-6Al-4V ELI, which has been used as an implant material mainly for artificial hip joints, and SUS 316L, which has been used as an implant material for many parts, including the instrumentation of scoliosis surgery. The equiaxed α structure, which is formed by annealing at a temperature below β transus, gives the best balance of strength and ductility in Ti-5Al-2.5Fe. The coarse Widmanstätten α structure, which is formed by solutionizing over β transus followed by air cooling and aging, gives the greatest fracture toughness in Ti-5Al-2.5Fe. This trend is similar to that reported in Ti-6Al-4V ELI. The rotating-bending fatigue strength is the greatest in the equiaxed α structure, which is formed by solutionizing below β transus followed by air cooling and aging in Ti-5Al-2.5Fe. Ti-5Al-2.5Fe exhibits much greater rotating-bending fatigue strength compared with SUS 316L, and equivalent rotating-bending fatigue strength to that of Ti-6Al-4V ELI in both the air and simulated body environments. The rotating-bending fatigue strength of SUS 316L is degraded in the simulated body environment. The corrosion fatigue, therefore, occurs in SUS 316L in the simulated body environment. Fatigue strength of Ti-5Al-2.5Fe in the simulated body environment is degraded by lowering oxygen content in the

  7. BBilateral Neglected Anterior Shoulder Dislocation with Greater Tuberosity Fractures

    PubMed Central

    Upasani, Tejas; Bhatnagar, Abhinav; Mehta, Sonu

    2016-01-01

    Introduction: Shoulder dislocations are a very common entity in routine orthopaedic practice. Chronic unreduced anterior dislocations of the shoulder are not very common. Neurological and vascular complications may occur as a result of an acute anterior dislocation of the shoulder or after a while in chronic unreduced shoulder dislocation. Open reduction is indicated for most chronic shoulder dislocations. We report a case of neglected bilateral anterior shoulder dislocation with bilateral displaced greater tuberosity fracture. To the best of our knowledge, only a handful cases have been reported in literature with bilateral anterior shoulder dislocation with bilateral fractures. Delayed diagnosis/reporting is a scenario which makes the list even slimmer and management all the more challenging. Case Report: We report a case of a 35-year-old male who had bilateral anterior shoulder dislocation and bilateral greater tuberosity fracture post seizure and failed to report it for a period of 30 days. One side was managed conservatively with closed reduction and immobilization and the other side with open reduction. No neurovascular complications pre or post reduction of shoulder were seen. Conclusion: Shoulder dislocations should always be suspected post seizures and if found should be treated promptly. Treatment becomes difficult for any shoulder dislocation that goes untreated for considerable period of time PMID:27703939

  8. Greater focus needed on methane leakage from natural gas infrastructure.

    PubMed

    Alvarez, Ramón A; Pacala, Stephen W; Winebrake, James J; Chameides, William L; Hamburg, Steven P

    2012-04-24

    Natural gas is seen by many as the future of American energy: a fuel that can provide energy independence and reduce greenhouse gas emissions in the process. However, there has also been confusion about the climate implications of increased use of natural gas for electric power and transportation. We propose and illustrate the use of technology warming potentials as a robust and transparent way to compare the cumulative radiative forcing created by alternative technologies fueled by natural gas and oil or coal by using the best available estimates of greenhouse gas emissions from each fuel cycle (i.e., production, transportation and use). We find that a shift to compressed natural gas vehicles from gasoline or diesel vehicles leads to greater radiative forcing of the climate for 80 or 280 yr, respectively, before beginning to produce benefits. Compressed natural gas vehicles could produce climate benefits on all time frames if the well-to-wheels CH(4) leakage were capped at a level 45-70% below current estimates. By contrast, using natural gas instead of coal for electric power plants can reduce radiative forcing immediately, and reducing CH(4) losses from the production and transportation of natural gas would produce even greater benefits. There is a need for the natural gas industry and science community to help obtain better emissions data and for increased efforts to reduce methane leakage in order to minimize the climate footprint of natural gas. PMID:22493226

  9. Greater focus needed on methane leakage from natural gas infrastructure.

    PubMed

    Alvarez, Ramón A; Pacala, Stephen W; Winebrake, James J; Chameides, William L; Hamburg, Steven P

    2012-04-24

    Natural gas is seen by many as the future of American energy: a fuel that can provide energy independence and reduce greenhouse gas emissions in the process. However, there has also been confusion about the climate implications of increased use of natural gas for electric power and transportation. We propose and illustrate the use of technology warming potentials as a robust and transparent way to compare the cumulative radiative forcing created by alternative technologies fueled by natural gas and oil or coal by using the best available estimates of greenhouse gas emissions from each fuel cycle (i.e., production, transportation and use). We find that a shift to compressed natural gas vehicles from gasoline or diesel vehicles leads to greater radiative forcing of the climate for 80 or 280 yr, respectively, before beginning to produce benefits. Compressed natural gas vehicles could produce climate benefits on all time frames if the well-to-wheels CH(4) leakage were capped at a level 45-70% below current estimates. By contrast, using natural gas instead of coal for electric power plants can reduce radiative forcing immediately, and reducing CH(4) losses from the production and transportation of natural gas would produce even greater benefits. There is a need for the natural gas industry and science community to help obtain better emissions data and for increased efforts to reduce methane leakage in order to minimize the climate footprint of natural gas.

  10. Cytotoxicity of PM(2.5) and PM(2.5--10) ambient air pollutants assessed by the MTT and the Comet assays.

    PubMed

    Hsiao, W L; Mo, Z Y; Fang, M; Shi, X M; Wang, F

    2000-11-20

    Ambient air particulate matters are classified into two distinct modes in size distribution, namely the coarse and fine particles. Correlation between high particulate concentration and adverse effects on human populations has long been recognized, however, the toxicology of these adverse effects has not been clarified. In the current report, the cytotoxic effects of the solvent-extractable organic compounds (SEOC) from fine particles smaller than 2.5 microm (PM(2.5)) and from coarse particles between 2.5-10 microm (PM(2.5-10)) were studied. Nine 24h consecutive monthly samples were tested to determine the correlation between cytotoxicity and total SEOC in two size fractions of particulate air pollution. Cytotoxicity of SEOC was measured by two micro-scale mammalian cells-based bioassays: the MTT cell proliferation assay, and the Comet assay for the detection of DNA damage. A well-defined mammalian cell line - Rat 6 rodent fibroblast was employed in the study. The SEOC extracts of air particulate matters were sub divided into two equal parts. One part was dissolved in DMSO, the other in KOH/hexane and then conjugated with bovine serum albumin to produce a lipid-soluble fraction for testing. The DMSO fraction would contain mainly the polycyclic aromatic hydrocarbons (PAH), alkanes and alkanols, while the lipid-soluble fraction would be enriched with fatty acids. The results from MTT assay showed that cytotoxicity of the PM(2.5) was much more severe than the PM(2.5-10), suggesting that toxic SEOC were confined to the fine particles. By and large, the DMSO solubles were much more toxic than the lipid solubles. The degree of cytotoxicity of the DMSO soluble samples is positively correlated to the amount of particulates present in the ambient air. For the PM(2.5), the winter samples were significantly more toxic than the summer samples in terms of cell killing, which seemed to be a direct reflection of the total loading of organic matter in the samples. Results from

  11. A Querying Method over RDF-ized Health Level Seven v2.5 Messages Using Life Science Knowledge Resources

    PubMed Central

    2016-01-01

    Background Health level seven version 2.5 (HL7 v2.5) is a widespread messaging standard for information exchange between clinical information systems. By applying Semantic Web technologies for handling HL7 v2.5 messages, it is possible to integrate large-scale clinical data with life science knowledge resources. Objective Showing feasibility of a querying method over large-scale resource description framework (RDF)-ized HL7 v2.5 messages using publicly available drug databases. Methods We developed a method to convert HL7 v2.5 messages into the RDF. We also converted five kinds of drug databases into RDF and provided explicit links between the corresponding items among them. With those linked drug data, we then developed a method for query expansion to search the clinical data using semantic information on drug classes along with four types of temporal patterns. For evaluation purpose, medication orders and laboratory test results for a 3-year period at the University of Tokyo Hospital were used, and the query execution times were measured. Results Approximately 650 million RDF triples for medication orders and 790 million RDF triples for laboratory test results were converted. Taking three types of query in use cases for detecting adverse events of drugs as an example, we confirmed these queries were represented in SPARQL Protocol and RDF Query Language (SPARQL) using our methods and comparison with conventional query expressions were performed. The measurement results confirm that the query time is feasible and increases logarithmically or linearly with the amount of data and without diverging. Conclusions The proposed methods enabled query expressions that separate knowledge resources and clinical data, thereby suggesting the feasibility for improving the usability of clinical data by enhancing the knowledge resources. We also demonstrate that when HL7 v2.5 messages are automatically converted into RDF, searches are still possible through SPARQL without

  12. Emission characteristics of carboxylates in PM2.5 from incense burning with the effect of light on acetate

    NASA Astrophysics Data System (ADS)

    Kuo, Su-Ching; Tsai, Ying I.; Sopajaree, Khajornsak

    2016-08-01

    Incense burning produces potentially harmful particulate matter. In this study we investigated the emissions of PM2.5 and gaseous acetic acid from four brands of traditional incense; Liao and Shang Lao Shan (SLS), sold in Taiwan, and Thai Yellow (Thai Y) and Thai Black (Thai B), sold in Thailand. Additionally, photochemical reactions of PM2.5 carboxylates emitted from incense burning were studied via a simulated light experiment. The average PM2.5 mass emission factor of each incense type was inversely correlated with the ash production of that incense. The Thailand incense carboxylate emissions were markedly higher than the Taiwan incense. Acetate accounted for 87.46% of total carboxylate emissions, with acetate emitted from the Thailand incense 1.26 times higher than from the Taiwan incense. Phthalate was detected in the PM2.5, indicating the presence of plasticizer. Concentrations of PM2.5 acetate, formate, pyruvate, glutarate, succinate, fumarate and tartarate were reduced in simulated light (51.5%-97.1% of those under dark), indicating that these seven types of carboxylate are easily photodegradable. In contrast, malonate, maleate, oxalate and phthalate concentrations in light were 1.17-1.84 times higher than in darkness, indicating photochemical reactions contribute to the formation of these species. The formation of the low-molecular weight dicarboxylates oxalate and malonate was most noticeable. Acetic acid, highly irritating to the respiratory system and skin, was present at high levels for all four incense types, as shown by the gaseous acetic acid/PM2.5 acetate ratios of 1.03-3.61. Burning incense indoors can generate high concentrations of PM2.5 acetate that increases the risks of respiratory and contact irritation, particularly when burning the Thailand incense. Moreover, burning incense in poorly ventilated, dimly lit indoor areas (e.g., temples and homes) can markedly increase the risk of irritation because the gaseous acetic acid is not degraded as

  13. Effects of Urban Landscape Pattern on PM2.5 Pollution—A Beijing Case Study

    PubMed Central

    Wu, Jiansheng; Xie, Wudan; Li, Weifeng; Li, Jiacheng

    2015-01-01

    PM2.5 refers to particulate matter (PM) in air that is less than 2.5μm in aerodynamic diameter, which has negative effects on air quality and human health. PM2.5 is the main pollutant source in haze occurring in Beijing, and it also has caused many problems in other cities. Previous studies have focused mostly on the relationship between land use and air quality, but less research has specifically explored the effects of urban landscape patterns on PM2.5. This study considered the rapidly growing and heavily polluted Beijing, China. To better understand the impact of urban landscape pattern on PM2.5 pollution, five landscape metrics including PLAND, PD, ED, SHEI, and CONTAG were applied in the study. Further, other data, such as street networks, population density, and elevation considered as factors influencing PM2.5, were obtained through RS and GIS. By means of correlation analysis and stepwise multiple regression, the effects of landscape pattern on PM2.5 concentration was explored. The results showed that (1) at class-level, vegetation and water were significant landscape components in reducing PM2.5 concentration, while cropland played a special role in PM2.5 concentration; (2) landscape configuration (ED and PD) features at class-level had obvious effects on particulate matter; and (3) at the landscape-level, the evenness (SHEI) and fragmentation (CONTAG) of the whole landscape related closely with PM2.5 concentration. Results of this study could expand our understanding of the role of urban landscape pattern on PM2.5 and provide useful information for urban planning. PMID:26565799

  14. Modeling and analysis of PM2.5 generation for key factors identification in China

    NASA Astrophysics Data System (ADS)

    Xia, Dehong; Jiang, Binfan; Xie, Yulei

    2016-06-01

    Recently, the PM2.5 pollution in China has occurred frequently and caused widely concern. In order to identify the key factors for PM2.5 generation, the formation characteristics of PM2.5 would be revealed. A property of electric neutrality of PM2.5 was proposed under the least-energy principle and verified through electricity-charge calculation in this paper. It indicated that PM2.5 is formed by the effect of electromagnetic force, including the effect of ionic bond, hydrogen bond and polarization. According to the analysis of interactive forces among different chemical components, a simulation model is developed for describing the random process of PM2.5 generation. In addition, an orthogonal test with two levels and four factors has been designed and carried out through the proposed model. From the text analysis, PM2.5 would be looser and suspend longer in atmosphere due to Organic Compound (OC) existing (OC can reduce about 67% of PM2.5 density). Considering that NH4+ is the only cation in the main chemical components of PM2.5, it would be vital for anions (such as SO42- and NO3-) to aggregate together for facilitating PM2.5 growing. Therefore, in order to relieve PM2.5 pollution, control strategies for OC and NH4+ would be enhanced by government through improving the quality of oils and solvent products, decreasing the amount of nitrogenous fertilizer utilization, or changing the fertilizing environment from dry condition to wet condition.

  15. Effects of Urban Landscape Pattern on PM2.5 Pollution--A Beijing Case Study.

    PubMed

    Wu, Jiansheng; Xie, Wudan; Li, Weifeng; Li, Jiacheng

    2015-01-01

    PM2.5 refers to particulate matter (PM) in air that is less than 2.5 μm in aerodynamic diameter, which has negative effects on air quality and human health. PM2.5 is the main pollutant source in haze occurring in Beijing, and it also has caused many problems in other cities. Previous studies have focused mostly on the relationship between land use and air quality, but less research has specifically explored the effects of urban landscape patterns on PM2.5. This study considered the rapidly growing and heavily polluted Beijing, China. To better understand the impact of urban landscape pattern on PM2.5 pollution, five landscape metrics including PLAND, PD, ED, SHEI, and CONTAG were applied in the study. Further, other data, such as street networks, population density, and elevation considered as factors influencing PM2.5, were obtained through RS and GIS. By means of correlation analysis and stepwise multiple regression, the effects of landscape pattern on PM2.5 concentration was explored. The results showed that (1) at class-level, vegetation and water were significant landscape components in reducing PM2.5 concentration, while cropland played a special role in PM2.5 concentration; (2) landscape configuration (ED and PD) features at class-level had obvious effects on particulate matter; and (3) at the landscape-level, the evenness (SHEI) and fragmentation (CONTAG) of the whole landscape related closely with PM2.5 concentration. Results of this study could expand our understanding of the role of urban landscape pattern on PM2.5 and provide useful information for urban planning.

  16. Indicators reflecting local and transboundary sources of PM2.5 and PMCOARSE in Rome - Impacts in air quality

    NASA Astrophysics Data System (ADS)

    Dimitriou, Konstantinos; Kassomenos, Pavlos

    2014-10-01

    The keystone of this paper was to calculate and interpret indicators reflecting sources and air quality impacts of PM2.5 and PMCOARSE (PM10-PM2.5) in Rome (Italy), focusing on potential exogenous influences. A backward atmospheric trajectory cluster analysis was implemented. The likelihood of daily PM10 exceedances was studied in conjunction with atmospheric patterns, whereas a Potential Source Contribution Function (PSCF) based on air mass residence time was deployed on a grid of a 0.5° × 0.5° resolution. Higher PM2.5 concentrations were associated with short/medium range airflows originated from Balkan Peninsula, whereas potential PMCOARSE sources were localized across the Mediterranean and coastal North Africa, due to dust and sea spray transportation. According to the outcome of a daily Pollution Index (PI), a slightly increased degradation of air quality is induced due to the additional quantity of exogenous PM but nevertheless, average levels of PI in all trajectory clusters belong in the low pollution category. Gaseous and particulate pollutants were also elaborated by a Principal Component Analysis (PCA), which produced 4 components: [Traffic], [photochemical], [residential] and [Secondary Coarse Aerosol], reflecting local sources of air pollution. PM2.5 levels were strongly associated with traffic, whereas PMCOARSE were produced autonomously by secondary sources.

  17. Effect of 2, 5-Substituents on the Stability of Cyclic Nitrone Superoxide Spin Adducts: A Density Functional Theory Approach

    PubMed Central

    Du, Li-Bo; Wang, Lan-Fen; Liu, Yang-Ping; Jia, Hong-Ying; Liu, Yang; Liu, Ke Jian; Tian, Qiu

    2011-01-01

    To design efficient spin traps for superoxide radicals, interest in the elucidation of substituent effects on the stability of superoxide spin adducts has become a necessary priority. In the present study, five cyclic nitrone superoxide spin adducts, i.e. DMPO-OOH, M3PO-OOH, EMPO-OOH, DEPMPO-OOH, and DEPDMPO-OOH, were chosen as model compounds to investigate the effect of 2,5-subsitituents on their stability, through structural analysis and decay thermodynamics using density functional theory (DFT) calculations. Analysis of the optimized geometries reveals that none of the previously proposed stabilizing factors, including intramolecular H-bonds, intramolecular nonbonding interactions, bulky steric protection, nor the C(2)–N(1) bond distance can be used to clearly explain the effect of 2,5-substituents on the stability of the spin adducts. Additionally the effect of the 2,5-substituents on the stability of the superoxide spin adducts cannot be simply clarified by Milliken charges on both atoms (nitroxyl nitrogen and nitroxyl oxygen). Subsequent study found that spin densities on the nitroxyl nitrogen and oxygen are well correlated with the half-life times of the spin adducts, and consequently are the proper parameters to characterize the effect of 2,5-substituents on their stability. Examination of the decomposition thermodynamics further supports the effect of the substituents on the persistence of cyclic nitrone superoxide spin adducts. PMID:20370568

  18. Satellite-derived high resolution PM2.5 concentrations in Yangtze River Delta Region of China using improved linear mixed effects model

    NASA Astrophysics Data System (ADS)

    Ma, Zongwei; Liu, Yang; Zhao, Qiuyue; Liu, Miaomiao; Zhou, Yuanchun; Bi, Jun

    2016-05-01

    Satellite remotely sensed aerosol optical depth (AOD) provides an effective way to fill the spatial and temporal gaps left by ground PM2.5 monitoring network. Previous studies have established robust advanced statistical models to estimate PM2.5 using AOD data in China. However, their coarse resolutions (∼10 km or greater) of PM2.5 estimations are not enough to support the health effect studies at urban scales. In this study, 3 km AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS) collection 6 products were used to estimate the high resolution PM2.5 concentrations in Yangtze Delta Region of China. We proposed a nested linear mixed effects (LME) model including nested month-, week-, and day-specific random effects of PM2.5-AOD relationships. Validation results show that the LME model only with day-specific random effects (non-nested model) used in previous studies has poor performance in the days without PM2.5-AOD matchups (the R2 of day-of-year-based cross validation (DOY-based CV) is 0.148). The results also show that our nested model cannot improve the performance of non-nested model in the days with PM2.5-AOD matchups (sample-based CV R2 = 0.671 for nested model vs. 0.661 for non-nested model), but can greatly improve the model performance beyond those days (DOY-based CV R2 = 0.339 for nested model vs. 0.148 for non-nested model). To further improve the model performance, we applied the "buffer models" (i.e., models fitted from datasets which ground PM2.5 were matched with the average AOD values within certain radius buffer zones of gridded PM2.5 data) on the 3 km AOD data since the "buffer models" has more days with PM2.5-AOD matchups and can provide more day-specific relationships. The results of this study show that 3 km MODIS C6 AOD data can be used to estimate PM2.5 concentrations and can provide more detailed spatial information for urban scale studies. The application of our nested LME model can greatly improve the accuracy of 3

  19. Satellite-derived high resolution PM2.5 concentrations in Yangtze River Delta Region of China using improved linear mixed effects model

    NASA Astrophysics Data System (ADS)

    Ma, Zongwei; Liu, Yang; Zhao, Qiuyue; Liu, Miaomiao; Zhou, Yuanchun; Bi, Jun

    2016-05-01

    Satellite remotely sensed aerosol optical depth (AOD) provides an effective way to fill the spatial and temporal gaps left by ground PM2.5 monitoring network. Previous studies have established robust advanced statistical models to estimate PM2.5 using AOD data in China. However, their coarse resolutions (˜10 km or greater) of PM2.5 estimations are not enough to support the health effect studies at urban scales. In this study, 3 km AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS) collection 6 products were used to estimate the high resolution PM2.5 concentrations in Yangtze Delta Region of China. We proposed a nested linear mixed effects (LME) model including nested month-, week-, and day-specific random effects of PM2.5-AOD relationships. Validation results show that the LME model only with day-specific random effects (non-nested model) used in previous studies has poor performance in the days without PM2.5-AOD matchups (the R2 of day-of-year-based cross validation (DOY-based CV) is 0.148). The results also show that our nested model cannot improve the performance of non-nested model in the days with PM2.5-AOD matchups (sample-based CV R2 = 0.671 for nested model vs. 0.661 for non-nested model), but can greatly improve the model performance beyond those days (DOY-based CV R2 = 0.339 for nested model vs. 0.148 for non-nested model). To further improve the model performance, we applied the "buffer models" (i.e., models fitted from datasets which ground PM2.5 were matched with the average AOD values within certain radius buffer zones of gridded PM2.5 data) on the 3 km AOD data since the "buffer models" has more days with PM2.5-AOD matchups and can provide more day-specific relationships. The results of this study show that 3 km MODIS C6 AOD data can be used to estimate PM2.5 concentrations and can provide more detailed spatial information for urban scale studies. The application of our nested LME model can greatly improve the accuracy of 3 km PM2.5

  20. A Shock Tube and Chemical Kinetic Modeling Study of the Oxidation of 2,5-Dimethylfuran

    PubMed Central

    Sirjean, Baptiste; Fournet, René; Glaude, Pierre-Alexandre; Battin-Leclerc, Frédérique; Wang, Weijing; Oehlschlaeger, Matthew A.

    2013-01-01

    A detailed kinetic model describing the oxidation of 2,5-dimethylfuran (DMF), a potential second-generation biofuel, is proposed. The kinetic model is based upon quantum chemical calculations for the initial DMF consumption reactions and important reactions of intermediates. The model is validated by comparison to new DMF shock tube ignition delay time measurements (over the temperature range 1300 – 1831 K and at nominal pressures of 1 and 4 bar) and the DMF pyrolysis speciation measurements of Lifshitz et al. [J. Phys. Chem. A 102 (52) (1998) 10655-10670] Globally, modeling predictions are in good agreement with the considered experimental targets. In particular, ignition delay times are predicted well by the new model, with model experiment deviations of at most a factor of two, and DMF pyrolysis conversion is predicted well, to within experimental scatter of the Lifshitz et al. data. Additionally, comparisons of measured and model predicted pyrolysis speciation provides validation of theoretically calculated channels for the oxidation of DMF. Sensitivity and reaction flux analyses highlight important reactions as well as the primary reaction pathways responsible for the decomposition of DMF and formation and destruction of key intermediate and product species. PMID:23327724

  1. A New n = 4 Layered Ruddlesden-Popper Phase K(2.5)Bi(2.5)Ti4O13 Showing Stoichiometric Hydration.

    PubMed

    Liu, Samuel; Avdeev, Maxim; Liu, Yun; Johnson, Mark R; Ling, Chris D

    2016-02-15

    A new bismuth-containing layered perovskite of the Ruddlesden-Popper type, K(2.5)Bi(2.5)Ti4O13, has been prepared by solid-state synthesis. It has been shown to hydrate to form stoichiometric K(2.5)Bi(2.5)Ti4O13·H2O. Diffraction data show that the structure consists of a quadruple-stacked (n = 4) perovskite layer, with potassium ions occupying the rock salt layer and its next-nearest A site. The hydrated sample was shown to remove the offset between stacked perovskite layers relative to the dehydrated sample. Computational methods show that the hydrated phase consists of intact H2O molecules in a vertical "pillared" arrangement bridging across the interlayer space. Rotations of H2O molecules about the c axis were evident in molecular dynamic calculations, which increased in rotation angle with increasing temperature. In situ diffraction data for the dehydrated phase point to a broad structural phase transition from orthorhombic to tetragonal at ∼600 °C. The relative bismuth-rich composition in the perovskite block results in a higher transition temperature compared to related perovskite structures. Water makes a significant contribution to the dielectric constant, which disappears after dehydration.

  2. 40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM-2.5

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... large city east of the Mississippi River, having characteristically high sulfate concentrations and high...-volatile organic pollutants. (B) Test site B shall be in a western city such as Denver, Salt Lake City, or... is characterized by relatively high PM2.5, nitrates, and semi-volatile organic pollutants. (B)...

  3. 40 CFR 53.35 - Test procedure for Class II and Class III methods for PM 2.5 and PM −2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... shall be in a large city east of the Mississippi River, having characteristically high sulfate...-volatile organic pollutants. (B) Test site B shall be in a western city such as Denver, Salt Lake City, or... that is characterized by relatively high PM 2.5, nitrates, and semi-volatile organic pollutants....

  4. 40 CFR 53.35 - Test procedure for Class II and Class III methods for PM 2.5 and PM −2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... shall be in a large city east of the Mississippi River, having characteristically high sulfate...-volatile organic pollutants. (B) Test site B shall be in a western city such as Denver, Salt Lake City, or... that is characterized by relatively high PM 2.5, nitrates, and semi-volatile organic pollutants....

  5. 40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM−2.5.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... large city east of the Mississippi River, having characteristically high sulfate concentrations and high...-volatile organic pollutants. (B) Test site B shall be in a western city such as Denver, Salt Lake City, or... is characterized by relatively high PM2.5, nitrates, and semi-volatile organic pollutants. (B)...

  6. 40 CFR 53.35 - Test procedure for Class II and Class III methods for PM2.5 and PM-2.5

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... large city east of the Mississippi River, having characteristically high sulfate concentrations and high...-volatile organic pollutants. (B) Test site B shall be in a western city such as Denver, Salt Lake City, or... is characterized by relatively high PM2.5, nitrates, and semi-volatile organic pollutants. (B)...

  7. 41 CFR 301-2.5 - What travel arrangements require specific authorization or prior approval?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 4 2010-07-01 2010-07-01 false What travel arrangements require specific authorization or prior approval? 301-2.5 Section 301-2.5 Public Contracts and Property Management Federal Travel Regulation System TEMPORARY DUTY (TDY) TRAVEL ALLOWANCES INTRODUCTION...

  8. Comparison of Hourly PM2.5 Observations Between Urban and Suburban Areas in Beijing, China

    PubMed Central

    Yao, Ling; Lu, Ning; Yue, Xiafang; Du, Jia; Yang, Cundong

    2015-01-01

    Hourly PM2.5 observations collected at 12 stations over a 1-year period are used to identify variations between urban and suburban areas in Beijing. The data demonstrates a unique monthly variation form, as compared with other major cities. Urban areas suffer higher PM2.5 concentration (about 92 μg/m3) than suburban areas (about 77 μg/m3), and the average PM2.5 concentration in cold season (about 105 μg/m3) is higher than warm season (about 78 μg/m3). Hourly PM2.5 observations exhibit distinct seasonal, diurnal and day-of-week variations. The diurnal variation of PM2.5 is observed with higher concentration at night and lower value at daytime, and the cumulative growth of nighttime (22:00 p.m. in winter) PM2.5 concentration maybe due to the atmospheric stability. Moreover, annual average PM2.5 concentrations are about 18 μg/m3 higher on weekends than weekdays, consistent with driving restrictions on weekdays. Additionally, the nighttime peak in weekdays (21:00 p.m.) is one hour later than weekends (20:00 p.m.) which also shows the evidence of human activity. These observed facts indicate that the variations of PM2.5 concentration between urban and suburban areas in Beijing are influenced by complex meteorological factors and human activities. PMID:26426035

  9. 40 CFR 721.10062 - 2,5-Furandione, polymer with oxybis[propanol], benzoate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false 2,5-Furandione, polymer with oxybis... Specific Chemical Substances § 721.10062 2,5-Furandione, polymer with oxybis , benzoate. (a) Chemical...-furandione, polymer with oxybis , benzoate (PMN P-04-627; CAS No. 103458-14-6) is subject to reporting...

  10. 40 CFR 721.10062 - 2,5-Furandione, polymer with oxybis[propanol], benzoate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false 2,5-Furandione, polymer with oxybis... Specific Chemical Substances § 721.10062 2,5-Furandione, polymer with oxybis , benzoate. (a) Chemical...-furandione, polymer with oxybis , benzoate (PMN P-04-627; CAS No. 103458-14-6) is subject to reporting...

  11. 40 CFR 721.10062 - 2,5-Furandione, polymer with oxybis[propanol], benzoate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false 2,5-Furandione, polymer with oxybis... Specific Chemical Substances § 721.10062 2,5-Furandione, polymer with oxybis , benzoate. (a) Chemical...-furandione, polymer with oxybis , benzoate (PMN P-04-627; CAS No. 103458-14-6) is subject to reporting...

  12. METHODS INTERCOMPARISON OF SAMPLERS FOR EPA'S NATIONAL PM 2.5 CHEMICAL SPECIATION NETWORK

    EPA Science Inventory

    The objective of this sampler intercomparison field study is to determine the performance characteristics for the collection of the chemical components of PM2.5 by the chemical speciation monitors developed for the national PM2.5 network relative to each other, to the Federal R...

  13. A simple method for the detection of PM2.5 air pollutions using MODIS data

    NASA Astrophysics Data System (ADS)

    Kato, Yoshinobu

    2016-05-01

    In recent years, PM2.5 air pollution is a social and transboundary environmental issue with the rapid economic growth in many countries. As PM2.5 is small and includes various ingredients, the detection of PM2.5 air pollutions by using satellite data is difficult compared with the detection of dust and sandstorms. In this paper, we examine various images (i.e., single-band images, band-difference images, RGB composite color images) to find a good method for detecting PM2.5 air pollutions by using MODIS data. A good method for the detection of PM2.5 air pollution is {R, G, B = band10, band9, T11}, where T11 is the brightness temperature of band31. In this composite color image, PM2.5 air pollutions are represented by light purple or pink color. This proposed method is simpler than the method by Nagatani et al. (2013), and is useful to grasp the distribution of PM2.5 air pollutions in the wide area (e.g., from China and India to Japan). By comparing AVI image with the image by proposed method, DSS and PM2.5 air pollutions can be classified.

  14. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory requirements for the PM2.5 NAAQS. (a) For purposes of meeting the emission inventory requirements of section... 40 Protection of Environment 2 2012-07-01 2012-07-01 false Emission inventory requirements for...

  15. PERSONAL EXPOSURES TO PM 2.5 MASS AND TRACE ELEMENTS IN BALTIMORE, MARYLAND

    EPA Science Inventory

    The relationship between a community monitor and personal exposures to PM2.5 mass and trace elements was investigated for 28 days during the summer of 1998 in a retirement home in Baltimore, Maryland. Daily community, outdoor and indoor PM2.5 were measured with a URG Versatile...

  16. Relationship Between PM2.5 Collected at Residential Outdoor Locations and a Central Site

    EPA Science Inventory

    Regression models are developed to describe the relationship between ambient PM2.5 (particulate matter [PM] ≤ 2.5 μm in aerodynamic diameter) mass concentrations measured at a central-site monitor with those at residential outdoor monitors. Understanding the...

  17. NARSTO Texas PM2.5 Sampling and Analysis Study 1997-1998

    Atmospheric Science Data Center

    2014-04-25

    NARSTO Texas PM2.5 Sampling and Analysis Study 1997-1998 Project Title:  NARSTO Discipline:  Tropospheric Chemistry Field Campaigns Aerosols Level:  L2 ... Related Data:  Texas PM2.5 Sampling and Analysis Study SCAR-B Block:  SCAR-B ...

  18. 40 CFR 52.379 - Control strategy: PM2.5.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (PM2.5) transportation conformity emission budgets for the Connecticut portion of the New York-Northern... the New York-Northern New Jersey-Long Island, NY-NJ-CT PM2.5 nonattainment area. (b) Determination of Attainment. EPA has determined, as of December 15, 2010, that the New York-Northern New Jersey-Long...

  19. 40 CFR 52.379 - Control strategy: PM2.5.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (PM2.5) transportation conformity emission budgets for the Connecticut portion of the New York-Northern... the New York-Northern New Jersey-Long Island, NY-NJ-CT PM2.5 nonattainment area. (b) Determination of Attainment. EPA has determined, as of December 15, 2010, that the New York-Northern New Jersey-Long...

  20. Effects of Meteorological Conditions on PM2.5 Concentrations in Nagasaki, Japan.

    PubMed

    Wang, Jianhua; Ogawa, Susumu

    2015-08-01

    The fine particulate matter (PM2.5) problem has attracted much scientific and public attention, due to its effects on visibility, human health, and global climate. There are three factors that have important effect on PM2.5 mass concentration: domestic pollutant emission sources, external sources outside of the country, and the meteorological conditions. Nagasaki is a coastal prefecture located at the westernmost part of Japan, which is an ideal location to study pollutants from long range transport and correlation between PM2.5 and meteorological conditions. In this paper, PM2.5 concentration data and meteorological data were obtained during 1 January 2013~31 December 2013. The spatial distribution depicts that the western part of the study area has the most serious PM2.5 pollution. The correlation analysis results between PM2.5 concentration and meteorological data showed that temperature had a negative, and precipitation had a positive, correlation with PM2.5. There was a threshold in the correlations between humidity and wind speed and PM2.5. The correlation was positive or negative depending on the meteorological variable values, if these were lower or higher than the threshold. From the relationship with wind direction, it can be depicted that the west wind might bring the most pollutants to Nagasaki. PMID:26247953

  1. DEVELOPMENT OF ANALYTICAL STANDARDS FOR THE ANALYSIS OF ORGANIC COMPOUNDS PRESENT IN PM2.5

    EPA Science Inventory

    The paper discusses the development of analytical standards for the analysis of organic compounds present in particulate matter with aerodynamic diameters < 2.5 micrometers (PM2.5). The methods and analytical standards described in the paper are designed to be implemented in a b...

  2. Estimation of ambient PM2.5 concentrations in Maryland and verification by measured values.

    PubMed

    Walsh, Kenneth; Sherwell, John

    2002-10-01

    In 1997, Maryland had no available ambient Federal Reference Method data on particulate matter less than 2.5 microm in aerodynamic diameter (PM23), but did have annual ambient data for PM smaller than 10 microm (PM10) at 24 sites. The PM10 data were analyzed in conjunction with local annual and seasonal zip-code-level emission inventories and with speciated PM2.5 data from four nearby monitors in the IMPROVE network (located in the national parks, wildlife refuges, and wilderness areas) in an effort to estimate annual average and seasonal high PM2.5 concentrations at the 24 PM10 monitor sites operating from 1992 to 1996. All seasonal high concentrations were estimated to be below the 24-hr PM2.5 National Ambient Air Quality Standards (NAAQS) at the sites operating in Maryland between 1992 and 1996. The estimates also indicated that 12 monitor sites might exceed the 3-year annual average PM2.5 NAAQS of 15 microg/m3, but Maryland's air quality shows signs that it has been improving since 1992. The estimates also were compared with actual measurements after the PM2.5 monitor network was installed. The estimates were adequate for describing the chemical composition of the PM2.5, forecasting compliance status with the 24-hr and annual standards, and determining the spatial variations in PM2.5 across central Maryland.

  3. 78 FR 73698 - Prevention of Significant Deterioration for Particulate Matter Less Than 2.5 Micrometers...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... indicator, PM 2.5 , 62 FR 38652 (July 18, 1997). The EPA revised the PM 2.5 NAAQS in 2006, 71 FR 61144 (October 17, 2006), and also in 2013, 78 FR 103086 (January 15, 2013). On October 20, 2010, the EPA... ) Increments, Significant Impact Levels (SILs) and Significant Monitoring Concentration (SMC), 75 FR 64864...

  4. 7 CFR 2.5 - Order in which officers of the Department shall act as Secretary.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., and Economics. (9) General Counsel of the Department of Agriculture. (10) Chief of Staff, Office of... 7 Agriculture 1 2011-01-01 2011-01-01 false Order in which officers of the Department shall act as Secretary. 2.5 Section 2.5 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY...

  5. PM2.5 and PM10 Emission from Agricultural Soils by Wind Erosion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil tillage and wind erosion are a major source of particulate matter less than 2.5 and 10 µm (PM2.5 and PM10) emission from cultivated soil. Fifteen cultivated soils collected from 5 states were tested as crushed (<2.0 mm) and uncrushed (natural aggregation) at 8, 10, and 13 m s-1 wind velocity in...

  6. 1 CFR 2.5 - Publication of statutes, regulations, and related documents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... “Federal Register Index,” and the “LSA (List of CFR Sections Affected).” ... 1 General Provisions 1 2012-01-01 2012-01-01 false Publication of statutes, regulations, and related documents. 2.5 Section 2.5 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL...

  7. 1 CFR 2.5 - Publication of statutes, regulations, and related documents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... “Federal Register Index,” and the “LSA (List of CFR Sections Affected).” ... 1 General Provisions 1 2014-01-01 2012-01-01 true Publication of statutes, regulations, and related documents. 2.5 Section 2.5 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL...

  8. 1 CFR 2.5 - Publication of statutes, regulations, and related documents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... “Federal Register Index,” and the “LSA (List of CFR Sections Affected).” ... 1 General Provisions 1 2013-01-01 2012-01-01 true Publication of statutes, regulations, and related documents. 2.5 Section 2.5 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL...

  9. Contribution of Urban Road Traffic to PM2.5 Pollution

    EPA Science Inventory

    Overview of PM2.5 measurements from EPA's NAAQS monitoring sites across the US. The few measurements that exist show increased PM2.5 mass levels at near-road sites, consistent with measurements of other pollutants emitted by motor vehicles.

  10. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS (CONTINUED) New Jersey § 52.1602 Control strategy and regulations: PM2.5. (a) Approval—On May 18, 2006, New Jersey submitted an early PM2.5 implementation plan to set motor vehicle emissions budgets for the New Jersey portion of the New...

  11. 40 CFR 52.1602 - Control strategy and regulations: PM2.5.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... planning organization as follows: North Jersey Transportation Planning Authority: 1,207 tons per year of direct PM2.5 and 61,676 tons per year of NOX; Delaware Valley Regional Planning Commission: 89 tons per..., PM2.5 nonattainment area. The revised budgets, applicable to the Delaware Valley Regional...

  12. 40 CFR 52.379 - Control strategy: PM2.5.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Quality Standard. This determination, in accordance with 40 CFR 51.1004(c), suspends the requirements for... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: PM2.5. 52.379 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.379 Control strategy: PM2.5....

  13. 40 CFR 52.379 - Control strategy: PM2.5.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy: PM2.5. 52.379 Section 52.379 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Connecticut § 52.379 Control strategy: PM2.5....

  14. 7 CFR 2.5 - Order in which officers of the Department shall act as Secretary.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Environment. (6) Under Secretary of Agriculture for Farm and Foreign Agricultural Services. (7) Under... 7 Agriculture 1 2013-01-01 2013-01-01 false Order in which officers of the Department shall act as Secretary. 2.5 Section 2.5 Agriculture Office of the Secretary of Agriculture DELEGATIONS OF AUTHORITY...

  15. 40 CFR 51.1008 - Emission inventory requirements for the PM2.5 NAAQS.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PM2.5 NAAQS. 51.1008 Section 51.1008 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Provisions for Implementation of PM2.5 National Ambient Air Quality Standards § 51.1008 Emission inventory... 172(c)(3) of the Act for nonattainment areas, the State shall, no later than three years...

  16. Axonal transport of neurofilament is accelerated in peripheral nerve during 2,5-hexanedione intoxication.

    PubMed

    Monaco, S; Jacob, J; Jenich, H; Patton, A; Autilio-Gambetti, L; Gambetti, P

    1989-07-10

    The neurotoxic compound 2,5-hexanedione (2,5-HD) causes an axonopathy characterized by the presence of neurofilament (NF)-containing enlargements in the preterminal segments of central and peripheral axons. The 2,5-HD axonopathy is a good model for human acquired and inherited giant axonal neuropathies. Recently, we reported that following 2,5-HD administration, axonal transport of NF is markedly and selectively accelerated in the primary visual system. We have now studied slow axonal transport in the sciatic system of rats intoxicated with 0.5% 2,5-HD in drinking water. Following radiolabeling, transported proteins were examined after polyacrylamide gel electrophoresis and fluorography. The bulk of radiolabeled NF subunits was located 30-50 mm from the spinal cord in 2,5-HD treated animals and 10-25 mm in controls. The rate of transport of the three NF subunits was 0.7 mm/day in controls and 1.2 mm/day in 2,5-HD treated animals. The rate of transport of tubulin was not significantly changed. Electrophysiological studies of soleus nerve and muscle showed no evidence of denervation after 6 weeks of intoxication. It is concluded that, following 2,5-HD administration, transport of NF is preferentially accelerated in both central and peripheral axons. A pathogenetic mechanism based on the acceleration of NF transport is proposed, which may explain the formation and the distal or proximal location of NF-containing axonal enlargements in giant axonopathies.

  17. 40 CFR 721.10062 - 2,5-Furandione, polymer with oxybis[propanol], benzoate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01<